If the clinical picture clearly points to Giardia lamblia (see page 216), administer metronidazole (Flagyl) 250 mg three times a day for 7 days. (A woman who is possibly pregnant should not use this drug except under the advice of her physician.)

Sometimes diarrhea is caused by antibiotic administration. This is called “Clostridium difficile–associated disease,” “antibiotic-associated diarrhea,” or “antibiotic-associated colitis.” It is caused by infection with the organism Clostridium difficile, which thrives in the bowel after the normal germs are killed by the initial antibiotic therapy. Another causative factor may be administration of a proton pump inhibitor drug, which lowers gastric acid, which helps C. difficile to survive and therefore be able to elaborate its toxin. Therapy against C. difficile is metronidazole (Flagyl) 500 mg by mouth three times a day or 250 mg by mouth four times a day, or vancomycin 125 mg by mouth four times a day for 10 days. It is important to note that C. difficile spores are not destroyed by disinfectant hand gels; thus handwashing remains extremely important to prevent the spread of this infectious organism.

Probiotics are harmless microorganisms (mostly bacteria and yeast) that are thought to provide health benefits. Examples include Lactobacillus rhamnosus and casei, which are found in certain yogurt products, and CULTURELLE, which is an all-natural dietary supplement containing the probiotic, L. rhamnosus GG (LGG). Probiotics, therefore, are a class of “friendly” bacteria that live in the digestive tract where they help to restore and maintain a healthy balance of “good” versus “bad” bacteria. They may be helpful in helping the bowel recover its normal function if ingested during and after a bout of diarrhea, particularly if antibiotics are used to treat the victim. They may also lessen the propensity for a person to develop C. difficile infection after being treated with an antibiotic for gastroenteric infection.

Traveler’s Diarrhea

Traveler’s diarrhea (“turista,” “Kathmandu quickstep,” “Montezuma’s revenge,” “Delhi belly,” “Aztec two-step,” “Hong Kong dog,” and many other synonyms) is frequent, loose bowel movements (three or more loose stools in a 24-hour period associated with one or more of nausea, vomiting, abdominal cramps, fever, urge to defecate, cramping and straining with defecation, or bloody or mucus-laden stools) caused by waterborne or food-borne pathogens, most commonly produced by forms of the bacterium Escherichia coli, which is introduced into the diet as a fecal contaminant in water or on food. Someone has described it as “stool that fits the shape of the container.” When caused by E. coli, symptoms usually occur 12 to 36 hours after ingesting the bacteria, and include the gradual or sudden onset of frequent (four to five per day) loose or watery bowel movements, rarely explosive, and far less violent than diarrhea associated with classic food poisoning (see below). Fever, bloating, fatigue, and abdominal pain are of minor to moderate severity. Nausea and vomiting are less frequently found than with viral gastroenteritis. Most traveler’s diarrhea is caused by bacteria, but a small percentage may be caused by viruses or parasites.

The affliction will resolve spontaneously in 2 to 5 days if untreated, but may be hastened to a conclusion if an antibiotic is administered. The current recommendation is to treat adults with ciprofloxacin (Cipro) 500 mg twice a day for 1 to 3 days or a single dose of 1 g, norfloxacin 800 mg in a single dose, or azithromycin 1 g single dose (10 mg/kg [2.2 lb] of body weight in children once a day for 3 days). Trimethoprim-sulfamethoxazole (e.g., Bactrim or Septra) is no longer recommended for traveler’s diarrhea, because of bacterial resistance. Another effective drug is rifamixin in a dose of 200 mg by mouth three times per day for 3 days. For known traveler’s diarrhea, the addition of loperamide (Imodium A-D) to the antibiotic regimen can be of significant benefit, with the precaution that it should be used only in the absence of high fever or bloody diarrhea. Alternatively, the diarrhea can be treated with bismuth subsalicylate (Pepto-Bismol); give two 262 mg tablets (or the liquid equivalent) every 30 minutes for eight doses, which may be repeated the second day. Kaolin and pectin given orally in combination may make the stools less runny, but do not shorten the duration of the diarrhea. Yogurt and lactobacillus preparations are not effective treatments.

During the recovery period, it is fine to advance the diet fairly rapidly over a few days from clear liquids to bland foods to a normal diet.

To prevent traveler’s diarrhea, a person traveling to high-risk regions with questionable hygiene and municipal water-disinfection standards (developing countries of Latin America, Africa, the Middle East, and Asia) can take rifamixin 200 mg once a day or ciprofloxacin 500 mg (or norfloxacin 400 mg or ofloxacin 200 mg) once a day, during the journey. Southern Europe (Spain, Greece, Italy, Turkey) and parts of the Caribbean pose a lesser risk. Another drug that can be used is doxycycline (Vibramycin) 100 mg twice a day. This should be done under the guidance of a physician, who will explain the risks (allergic reactions, blood disorders, antibiotic-associated colitis, vaginal yeast infection, skin rashes, photosensitivity) versus the benefits (particularly for those prone to infectious diarrhea or who would suffer unduly from an episode of severe diarrhea). Ingesting lactobacilli may improve certain aspects of digestion, but does not prevent traveler’s diarrhea.

Alternatively, it has been recommended that you can drink 4 tbsp (60 mL) of Pepto-Bismol (bismuth subsalicylate) four times a day; this necessitates carrying one 8 oz bottle for each day. The tablets (two 262 mg tablets four times a day) are less palatable. However, this prophylaxis is not intended to substitute for dietary discretion. In addition, large doses of bismuth subsalicylate can be toxic, particularly to people who regularly use aspirin. Anyone with an aspirin allergy should not use bismuth subsalicylate. Side effects include blackened stools and a black tongue, nausea, constipation, and ringing in the ears.

People who would be advised to consider taking a drug to prevent infectious diarrhea include those with a significant underlying medical problem (such as acquired immunodeficiency syndrome [AIDS], inability to produce stomach acid, or inflammatory bowel disease) and those with an itinerary rigid enough that it would be catastrophic to the mission to be laid up with diarrhea.

Some experts and the medical literature argue that conventional advice to avoid specific foods and liquids doesn’t really help prevent traveler’s diarrhea. However, on the chance that certain behaviors might be helpful, here are some commonly accepted notions. In general, it is safe to brush your teeth with foreign or mountain water, so long as you spit and don’t swallow. Salads (particularly lettuce), raw vegetables, raw or undercooked meat (particularly hamburgers), raw or undercooked snails or seafood, unpeeled fruits and vegetables, cold sauces, ice cream, fresh cheese, spicy sauces in open containers, tap water, and ice are risky business. Fresh produce should, when possible, be purchased not bruised or damaged. Produce should not be packed with raw meat, poultry, or seafood products. Fruits and leafy vegetables should be washed in iodinated water, washed with dilute soap and previously boiled water, or immersed in boiling water for 30 seconds. In some underdeveloped countries, melons are injected with contaminated water to increase their weight before sale. Be cautious with buffets, food from street vendors, and the salads served on flights that originate from developing countries. Food prepared in restaurants in developing countries probably poses greater risk than does self-prepared food.

Probiotics have not yet been demonstrated to reduce the risk of traveler’s diarrhea.

If possible, wash your hands with soap and water before you handle food or eat. If a disinfectant gel or lotion is available, use it, even after handwashing. This will significantly reduce the risk for transmission of bacteria and viruses that cause infections. Disinfectant gels do not provide protection, however, against spore-forming bacteria, such as Clostridium difficile, so handwashing retains its importance when this bacterium is a possible environmental contaminant.

In addition to proper handwashing (or wiping with disinfectant gel or cream) and disinfection of drinking water, there come a number of important actions, such as “food rules” (proper washing, cooking, and serving; what foods to avoid), bathroom hygiene, not sharing items such as towels and toothbrushes, and so on.

One important topic is how best to wash dishes to remove diarrhea-causing bacteria and viruses. One effective washing-up system is removal of most food residue with detergent (5 milliliters or 1 teaspoon) in the water in bowl 1, followed by a finishing wash (scrub until clean) with bleach (10 milliliters or 2 teaspoons of 4% chlorine bleach) in the water in bowl 2, followed by a final rinse in drinkable water in bowl 3. The final rinse is felt to remove the taste of the detergent and bleach (the latter considered to be a disinfectant). A few final recommendations are to use hot water in bowl 1, use a scouring pad or brush in bowl 2 with the bleach to avoid contamination of the scourer, allow all utensils to air dry after washing, and clean the washing-up bowls and allow them to dry between uses. Another suggestion is to use up to 100 milliliters or 20 teaspoons (3 teaspoons = 1 tablespoon) of bleach in bowl 2 if there is a current outbreak of diarrhea and vomiting. This increases the disinfection power of the second bowl.

Water disinfection is discussed on page 433. Stick to boiled water, food that is served steaming hot, dry foods (bread), bottled carbonated beverages, and reputable food establishments. Alcohol in mixed drinks does not disinfect water. Packaged butter and packaged processed cheese are usually safe to eat. Unpasteurized dairy products should be avoided. Avoid casseroles, quiches, lasagna, and other foods that are prepared in advance and then may be allowed to sit for a prolonged period before consumption. During that time period, they can be contaminated by bacteria from fingers, insect legs, and contaminated serving utensils. With regard to seafood, raw or undercooked products, particularly shellfish, are especially hazardous. Vibrio organisms—which cause, among other problems, cholera—frequently reside in crabs and oysters. Cook all shellfish for a minimum of 10 minutes of boiling, or 30 minutes of exposure to full steam.

Viral Diarrhea

Traveler’s diarrhea can also be caused by viruses. Viral gastroenteritis (commonly caused by rotaviruses [perhaps the most common cause of severe gastroenteritis in children less than 5 years of age] or Norwalk-like viruses) includes diarrhea as a symptom. Norovirus is a problem with outbreaks of diarrhea on cruise ships. Viral gastroenteritis is often associated with nausea and vomiting, fever, stomach cramps, copious rectal gas, and a flu-like syndrome. The diarrhea is typically watery, frequent (up to 20 movements per day), and often foul smelling, discolored (green to greenish brown), and without significant mucus or blood. Generally, the victim will have cyclic waves of lower-abdominal cramps, relieved by bowel movements.

Therapy requires continual oral hydration with clear liquids such as apple juice or broth. If they are available, drink electrolyte-containing sports beverages. It is critical to keep the victim from becoming dehydrated. What comes out below should be replaced from above.

The cramps can be controlled with propantheline bromide (Pro-Banthine), loperamide (Imodium A-D), or diphenoxylate (Lomotil), which will also help limit the diarrhea. It should be noted, however, that these drugs will slow down the activity of the bowel and allow any toxins that are in the gut to remain in contact with the bowel wall. With certain bacterial and viral infections, these drugs may prolong the carrier state and actually increase the severity and duration of the disease. Therefore, it is prudent to avoid the use of Imodium A-D or Lomotil unless the intake of fluids cannot keep pace with the diarrhea, and dehydration is becoming a real concern. Never give an antimotility agent to an infant. Imodium A-D can be used in children age 2 years and older if the diarrhea is clear (no blood) and watery, there is no associated fever, and diarrhea is leading to debilitating dehydration. Give a child a 0.2 mg/kg (2.2 lb) of body weight dose every 6 hours. The liquid preparation contains 1 mg/tsp (5 mL).

Cryptosporidiosis

Cryptosporidiosis is caused by Cryptosporidium parvum, which is commonly found in surface water in the United States. Infection is caused by ingestion of the oocysts, and is manifested by diarrhea, abdominal cramps, nausea and vomiting, fatigue, and low-grade fever. The cysts are 2 microns in diameter. Symptoms begin 2 to 10 days after ingestion, and may last for up to 2 weeks, with a carrier state of up to 2 months. The treatment is nitazoxanide 500 mg by mouth twice a day for 3 days in adults, and 100 mg twice a day in children up to age 12. Another effective treatment is azithromycin 500 mg by mouth once a day for 5 days in adults or paromomycin 500 mg three times a day for 7 days.

Food Poisoning

Food poisoning is caused by toxins that are produced by a number of bacteria, with the most common being Staphylococcus. Improper preservation (generally, lack of refrigeration) of food allows bacterial proliferation, which is not corrected by cooking. Typically, the symptoms occur 2 to 6 hours after eating and consist of severe abdominal cramps with nausea and vomiting. Diarrhea may be delayed by an hour or two, or may occur simultaneously with the nausea and vomiting. The diarrhea is often explosive. As with viral gastroenteritis, the bowel movements may be foul smelling and blood tinged. The disease is self-limited, and generally subsides after 6 to 12 hours. Treatment consists of rehydration with clear liquids. Antimotility drugs, such as loperamide (Imodium A-D) or diphenoxylate (Lomotil), may prolong the disorder, and should not be used unless the victim cannot replenish fluid losses.

E. coli O157:H7

Escherichia coli O157:H7 is a bacterium that has been transmitted by as few as 10 bacteria in raw or undercooked hamburger meat, fruit juices, and other food with fecal contamination. It can be spread person to person, and has also been transmitted by petting animals, contacting animal manure, and swimming in recreational pool water. After ingesting the bacteria, an infection may occur after an incubation period of 1 to 10 days, with 3 days being the average delay between exposure and illness. It causes a syndrome of fever or no fever, abdominal pain, vomiting, and nonbloody diarrhea, followed in a few days by bloody diarrhea, dehydration, weakness, anemia, and kidney failure. There is not yet an effective treatment with antibiotics. In fact, therapy with some antibiotics may contribute to more severe illness. Prevention means strict handwashing before eating and cooking ground beef until it is no longer pink (160°F). Do not mix raw and cooked foods, particularly meat. After you cook meat, do not serve it on the unwashed dish that carried the raw food. Since raw meat, especially beef, can be a problem, be certain to wash hands, cooking utensils, cutting boards, dishes, and counters after they have been in contact with raw meat. Milk and fruit juices prepared from crushing processes require pasteurization. Understand that in the absence of pasteurization, which is a heating process, no product can be guaranteed to not be contaminated with the bacteria normally killed in the pasteurization process. Many of us like to drink fresh fruit juice. When we do so, we take a risk, usually, quite minor, that it may be contaminated. In the presence of someone with any cause of diarrhea, excellent handwashing technique should be observed. If a person is ill with a diarrheal illness, he or she should not prepare food for others or share common bodies of swimming or bathing water. Try to not swallow lake or swimming pool water.

For treatment of known or highly suspected E. coli O157:H7 infection, antibiotics are not recommended. This is because in some cases, antibiotics may worsen the affliction. The precise reason this happens is not known, but one suggestion is that by causing rapid death of large numbers of bacteria, the result is release of large amounts of the Shiga toxin (also known as verocytotoxin), which causes the medical problems. Antidiarrheal agents, such as loperamide (Imodium), are also not recommended, because they are thought to possibly keep the bacteria in contact with the bowel for longer periods of time. Most patients recover without antibiotics in approximately a week. Severely dehydrated individuals may require intravenous fluids. Children infected with E. coli 0157:H7 are at higher risk than are adults for developing hemolytic-uremic syndrome, in which they may suffer kidney failure.

The difficulty with the recommendation to withhold antibiotics is that it is very difficult to make a precise field diagnosis of any particular cause of diarrhea.

Giardia Lamblia

Giardia lamblia is a flagellate protozoan (one-celled organism) that has become a worldwide problem, particularly in wilderness settings in the western United States, Nepal, and the Soviet Union. It is transmitted as cysts in the feces of many animals, which include humans, elk, beavers, deer, cows, dogs, and sheep. Dormant Giardia cysts enter water, from which they are ingested by humans. Cysts can live for up to 3 months in cold water.

If more than 10 to 25 cysts are swallowed, the organisms establish residence in the duodenum and jejunum (first parts of the small bowel), and after an incubation period of 7 to 20 days emerge in another form (trophozoite) to cause stomach cramps, flatulence, a swollen lower abdomen, often explosive and foul-smelling watery (“floating”) diarrhea, “rotten” (sulfurous) belching, and nausea. Fever and vomiting are unusual except in the first few days of illness. Foul flatus and abdominal cramping are common. Because of the delay in onset after ingestion of the cysts, many a backpacker develops “backpacker’s diarrhea” or “beaver fever” after he returns to civilization, and he does not make the mental connection to his recent journey. If the diarrhea becomes chronic, the victim can lose appetite, lose weight, and become weak. Diagnosis is made by a physician who recognizes trophozoites or microscopic cysts in the stool of the victim, takes a sample of mucus from the duodenum, or is confident with a clinical diagnosis.

Untreated, the illness usually resolves after about 6 weeks. However, the diarrhea can go on for months. Therapy for Giardia infestation is the administration of metronidazole (Flagyl) 250 to 500 mg three times a day for 7 days. An alternative prescription drug is quinacrine hydrochloride (Atabrine) 100 mg twice a day for 7 days; the pediatric dose is 7 mg/kg (2.2 lb) of body weight per day in three divided doses for 7 days. Unfortunately, this drug has side effects (which occur in 1 to 4 out of every 1,000 people) that include making the person psychotic (lose touch with reality) for up to a few weeks. An excellent drug is tinidazole (Tiniba, Fasgyn), which is taken in a 2 g dose for 1 or 2 days; the pediatric dose is 50 mg/kg (2.2 lb) of body weight in a single dose. A good drug for children is furazolidone (Furoxone) 6 mg/kg of body weight in four divided doses for 7 days. There have been mixed reports of success with albendazole, given in a dose of 400 mg per day for 3 to 5 days. Particularly when an expedition will not reach civilization for 3 to 4 weeks, there is no reason to withhold treatment awaiting a definitive diagnosis. If the field diagnosis is correct, in most cases drug therapy will cause dramatic relief from symptoms within 3 days. There is no prophylactic drug that is recommended to prevent infestation.

Other Infectious Diarrheas

Diarrhea can be caused by a number of parasites and other infectious agents, which include Campylobacter, Shigella, Salmonella, Yersinia, Vibrio, and Entamoeba histolytica (and other amoebae). Campylobacter jejuni are the bacteria that most commonly cause diarrhea in the U.S., often noted after eating contaminated poultry. Although up to ¼ of persons who are infected are without symptoms, those who become ill frequently exhibit nausea, severe diarrhea, and abdominal pain. Amebic dysentery is caused by E. histolytica, the symptoms of which are diarrhea (frequently bloody, copious, and frequent) that does not respond to antibiotics, characterized by severe lower abdominal pain and a swollen abdomen. In an endemic area, presumptive field treatment is with metronidazole 500 mg by mouth three times a day for 10 days or with tinidazole 600 mg by mouth for 5 days. This is followed by eradication of the cyst forms remaining in the bowel wall with a drug such as paromomycin or diloxanide furoate.

Diarrhea-causing pathogens cause a constellation of fever, chills, nausea, vomiting, diarrhea (with or without mucus and blood), weakness, and abdominal pain. Because the clinical picture can be similar with infection from all of these organisms, the differentiation frequently relies on examination of the stool under the microscope and/or culture of the stool to identify the specific pathogen. For the sake of the brief expedition, the treatment is the same: rehydration with copious amounts of balanced electrolyte solutions, and antimotility agents only when essential to prevent severe dehydration. If the victim suffers from high fever with shaking chills, has persistent bloody or mucus-laden bowel movements, or is debilitated by dehydration, he should seek the care of a physician. Meanwhile, the administration of ciprofloxacin (Cipro) 500 mg two times a day or azithromycin 500 mg once a day for 3 days will treat E. coli and Shigella, may eradicate Salmonella, and will not adversely affect other infections. As soon as the victim of persistent diarrhea returns to civilization, he should visit a physician for a thorough evaluation. If the ova or parasitic forms of amoebae are seen during microscopic examination of stool, other drugs, such as tinidazole, metronidazole, diloxanide furoate, paromomycin, or diiodohydroxyquin, may be prescribed. If the ova or parasitic forms of worms are seen, drugs such as mebendazole or pyrantel pamoate may be prescribed.

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS, sometimes called spastic colitis, nervous colon, or irritable colon) is characterized by abdominal distention, the passage of flatus, cramping (pain) relieved by defecation, onset associated with change in frequency and/or form of the stool, and mucus-laden diarrhea. This can be debilitating. The sufferer may also complain intermittently of constipation. The onset of IBS is often associated with a change of the form of the stool (commonly loose or watery, or sometimes pellets). It is more common in women than men, and can be triggered by psychological stress. Many sufferers carry their own antidiarrheal or antispasmodic medication, such as loperamide or clidinium bromide with chlordiazepoxide (Librax). Constipation may be treated with laxatives such as lactulose or polyethylene glycol solution (see Constipation, below). Drugs that diminish hyperactivity of the bowel include dicyclomine hydrochloride and hyoscyamine sulfate. Diarrhea is treated with loperamide. Alosteron is used only for severe diarrhea-predominant IBS that does not respond after 6 months to conventional therapies. Irritable bowel is a diagnosis of exclusion that should be made by a physician. If a person is known to suffer from IBS with a constipation component, he should be encouraged to eat adequate fiber (indigestible plant carbohydrate: bran, steamed vegetables, or 20 to 30 g fiber supplement) and avoid coffee (caffeine), alcohol, fatty foods, and gas-producing vegetables. A useful prophylactic measure may be regular ingestion of a probiotic (e.g., Lactobacillus or Bifidobacterium infantis 35624) preparation. Regular exercise also appears to be helpful for some individuals. There are numerous therapies under investigation for persons with IBS that is refractory to all of these measures. These include antidepressants, serotonin-3 and serotonin-4 receptor antagonists, antibiotics, herbal therapy (including peppermint oil), and other agents to reduce the sensitivity and motility of the bowel.

CONSTIPATION

If a person becomes constipated (straining, difficult bowel movements with hard stools), the retention of stool and discomfort can be severe. Significant contributing factors to constipation are diet, dehydration, and lack of exercise. During outdoor activities, take care to drink fluids at regular intervals. In addition, sufficient fiber (bran, whole-grain cereals, vegetables, fruits) must be maintained in the diet. The “city backpacker” diet of chocolate bars, peanuts, and cheese sandwiches will turn the most irascible bowels into mortar. Regular, preemptive doses of a stool softener such as docusate sodium (Colace), or a bulking agent such as psyllium seed hydrophilic mucilloid (Metamucil), must be ingested with at least two glasses of water to be effective.

To relieve the victim of mild constipation, try the following measures:

1. Force fluids.

2. Adjust the diet (more for prevention than treatment).

3. Consider the use of a stool softener (mineral oil; docusate sodium: Colace, Regulax SS, Surfak); bulking agent (psyllium: Metamucil, Perdiem, Fiberall; methylcellulose: Citrucel; polycarbophil: Fibercon, Equalactin, Konsyl); osmotic laxative (magnesium hydroxide: Phillips’ Milk of Magnesia; magnesium citrate: Evac-Q-Mag; sodium phosphate: Fleet Enema, Fleet Phospho-Soda, Visicol), natural laxative (prune juice), poorly-absorbed sugar (lactulose: Cephulac, Chronulac, Duphalac); polyethylene glycol and electrolytes: Colyte, GoLYTELY, NuLYTELY; polyethylene glycol: Miralax, and/or stimulant laxative (cascara sagrada: Colamin, Sagrada-lax; senna: Senokot, Ex-Lax; castor oil: Purge, Neoloid, Emulsoil). Peri-Colace is a combination of the stool softener docusate sodium and casanthranol, a laxative. Other drugs are listed on page 500.

4. In general, it is best to avoid the use of repetitive enemas or potent laxatives, because they can cause large fluid losses. A useful enema is a Colace 5 mL (200 mg) “microenema.” A child may benefit from a plain glycerin suppository. In general, enemas can cause cramping and bloating. If they contain electrolytes, such as magnesium or phosphate, they can cause elevated levels of these in the bloodstream. Typical enemas include 6 to 12 ounces of milk and an equal portion of molasses; 2 tablespoons of Epsom salts per quart of lukewarm water; 45 mL of Phospho-Soda with 2 quarts of water; 9 mL packet of Castile soap in 2 quarts of tap water; 30 mL of mineral oil in 1 to 2 quarts of water; and 1 to 2 quarts of warm (body temperature) tap water.

5. If a victim becomes impacted (has not had a bowel movement for 5 to 10 days due to constipation), using stool softeners will probably be ineffective, and piling on an ingested load of bulky fiber is just dumping more backfill behind the dam. Unfortunately, to break the roadblock, you may have to perform the physical removal of stool from the rectum, using a softening enema first and then a gloved finger for the extraction. This should be done gently, to prevent injury to the anus and walls of the rectum. Two fingers are used to dilate the anus, then the stool is broken up with a scissoring motion. After as much stool as possible is removed manually, an enema should be used.

On a prolonged expedition, you should carry the stimulant laxative drug bisacodyl (Dulcolax). This is administered in oral (5 mg) or glycerin suppository (10 mg) form, with onset of effect in a few hours. Bisacodyl causes the bowel to contract, which can be extremely uncomfortable in someone with a large fecal impaction.

A useful drug to treat constipation is lactulose syrup 10 mg per tbsp (15 mL) of syrup. Administer 1 or 2 tbsp per day. Another method is polyethylene glycol solution (MiraLax) given as 17 g powder (1 heaping tbsp) dissolved in 8 oz (240 mL) of water taken daily for up to 4 days to initiate a bowel movement.

An elderly person with any significant change in bowel habits should see a physician on return to civilization.

HEMORRHOIDS

Hemorrhoids are enlarged veins that are found outside (external hemorrhoids) or inside (internal hemorrhoids) the anal opening (Figure 118). They cause problems that range from minor itching and skin irritation to excruciating pain, inflammation, and bleeding. The bleeding is noticed as bright red blood either on the outside of the stool (not mixed in with the excrement), in the toilet water, or on the toilet paper. Bleeding is usually sporadic, associated with difficult bowel movements (constipation) with straining, and passage of hard stools. To avoid problems, keep your stools soft. If hemorrhoids flare, the treatment is sitz (sitting) baths in warm water for 30 minutes three times a day, and the application of medication in the form of cream, ointment, or suppositories (Preparation H [essentially a petrolatum lubricant]; Anusol or Tronolane [with pramoxine 1% for pain and itching] or Anusol HC-1 [without pramoxine, but with hydrocortisone 1% for inflammation]; Nupercainal [1% dibucaine]; pramoxine hydrochloride 1% with hydrocortisone acetate 1% [proctoCream-HC]; ELA-Max 5 [lidocaine 5%] anorectal cream; Analpram-HC cream or ointment [hydrocortisone and pramoxine]). Unless bleeding is severe, it can be managed with sterile pads and gentle pressure. If the victim develops a fever associated with severe rectal pain or cannot pass a bowel movement, a physician should be sought.

Figure 118 Hemorrhoids. A, External view of the anus with an enlarged external hemorrhoid. B, A cross-sectional view of the anus and rectum shows dilated veins that protrude into the rectum (internal hemorrhoids) and externally from the anus.

A thrombosed hemorrhoid is one in which the blood has clotted within the dilated vein and formed a visible and palpable enlarged, hardened, and dark blue-purple knot. Pain is generally severe, and the victim may be unable to complete a bowel movement. The treatment usually involves incision through the wall of the vein and removal of the clot. Until the victim can be brought to a physician, warm soaks may ease the discomfort. Generally, all elderly people with rectal bleeding should be fully evaluated by a physician, to be sure that there is not another, more serious, cause.

FLATUS

The rectal passage of bowel gas offers relief and occasional embarrassment. If stomach cramps are due to excessive gas production, the drug of choice is simethicone (Mylicon or Mylicon-80), which causes dissolution of large gas collections and eases the passage of flatus. Charcoal Plus tablets and Flatulex tablets contain simethicone combined with activated charcoal, an absorbent. Beano food enzyme dietary supplement contains the enzyme alpha-galactosidase, which is advertised to be effective in preventing gas formation from vegetables, beans, and grains that contain indigestible sugars that ferment in the bowel to create gas. Because intestinal gas (methane) can be flammable, do not attempt to ignite rectal gas or direct the stream of gas into a campfire. Backflashes and minor burns are a real risk.

HEARTBURN

Heartburn is a manifestation of esophageal reflux (in medical parlance, sometimes called gastroesophageal reflux disease [GERD]), in which stomach contents containing acid and food travel backward from the stomach into the esophagus. This causes irritation and pain, which is typically sharp or burning and located under the breastbone and/or in the upper abdomen. It may be associated with belching, a sour taste in the mouth, and/or near-vomiting. When severe, the pain may be confused with angina (see page 49). Omeprazole (Prilosec) is a drug that suppresses gastric acid secretion. It can be prescribed for a 1- to 2-week period by a physician for GERD or for up to a 4- to 8-week period for severe erosive inflammation of the esophagus (adult dose 20 to 40 mg by mouth in the morning and 20 mg in the evening). Other drugs in this category (“proton pump inhibitors”) are pantoprazole (Protonix) and rabeprazole (AcipHex). Mild heartburn is often managed with antacids, particularly Gaviscon, which forms a “foam” that floats on the stomach contents and protects the esophagus from refluxed acid. Metoclopramide hydrochloride (Reglan) helps control muscle tone at the sphincter (junction) between the stomach and the esophagus, and thus helps prevent reflux. Nizatidine 75 mg (Axid AR [“acid reducer”]) is an H2-blocker drug (see page 501) that inhibits gastric acid secretion. It is swallowed 30 to 60 minutes before eating, and can be used up to twice in 24 hours. Cimetidine (Tagamet) 200 mg can be used in a similar manner. Famotidine (Pepcid AC) 10 or 20 mg twice a day (preferably ingested 15 to 60 minutes before eating) for up to 6 weeks is another therapy.

Keep meals small, and do not eat them immediately before reclining (no bedtime snacks). Known gastric irritants (alcohol, cigarettes, pepperoni sandwiches) should be avoided. If possible, sleep with the head of your bed or sleeping bag elevated. Occasionally, it is necessary to sleep in the sitting position, to counteract the forces of gravity and a loose esophageal sphincter. Wear loose-fitting clothing around the stomach. Weight loss is advised for overweight or obese persons.

NAUSEA AND VOMITING

Nausea and vomiting may arise from causes as simple as anxiety, or may represent a serious problem such as appendicitis, ingestion of a poisonous plant, or response to a head injury. When vomiting is secondary to a serious underlying disorder, the basic problem must be remedied. Any victim with nausea and vomiting who suffers from altered mental status, uncontrollable high fever, extreme abdominal pain, or chest pain that might represent heart disease—or who is either very young or very old—should be evacuated promptly. Anyone who vomits blood should be taken to a hospital immediately. Vomiting in children is particularly worrisome if it accompanies head trauma (see page 61), abdominal trauma (see page 119), or lethargy or confusion (which might represent an infection or poisoning); severe vomiting (which might represent a bowel obstruction [see page 127] or appendicitis [see page 126]) is also of concern.

If nausea and vomiting due to gastroenteritis become excessive, they can be managed with an antiemetic. One effective drug is ondansetron (Zofran). The adult dose is one 4 mg dissolving tablet every 8 hours; the pediatric dose is 0.15 mg/kg of body weight of the oral dissolving tablet every 6 to 8 hours. Alternative drugs are prochlorperazine (Compazine), which can be administered orally or as a suppository, promethazine (Phenergan), which comes in suppository form, or trimethobenzamide (Tigan), which can be taken orally or by suppository. If the victim is so ill that he cannot keep anything in his stomach, it makes no sense to administer an oral medication, so an injection or suppository must be used. A person who requires medication to control vomiting should see a physician. After multiple episodes of vomiting, the victim may suffer from dehydration (see page 207), particularly if there is associated diarrhea as part of a gastroenteritis. Fluid replacement is essential. The diet should be advanced slowly as the victim’s hunger returns.

Nausea and vomiting due to motion sickness are discussed on page 440. Cyclical vomiting is a disorder in which the victim experiences fatigue and nausea, and perhaps sweating and pale skin color for approximately 90 minutes before onset of explosive vomiting, which may last for up to 24 hours in children and 3 days in adults. The victims may vomit up to 6 times per hour. This disorder, which may sometimes be accompanied by abdominal pain, can be triggered by stress, an upper respiratory tract infection, menses, sleep deprivation, certain foods, asthma attacks, motion sickness, or environmental allergies. Treatment is supportive and based on symptoms. If an attack is severe, the victim may require intravenous hydration.

VOMITING BLOOD

Bleeding from the gastrointestinal tract can cause the victim to vomit blood (either bright red or dark brown “coffee grounds”). If the blood is not vomited, it passes through the bowels and emerges as dark black tarry stools (melena) or occasionally as maroon clots or bright red blood. Brisk bleeding in the stomach or bowels may be painless; any bleeding should be considered serious. Even if the bleeding episode is brief (except for bleeding from known hemorrhoids), the victim should be evacuated immediately to a hospital. If the victim is known to have ulcer disease and ceases vomiting, antacids should be given by mouth.

Persistent retching can cause the stomach wall to tear and begin to bleed. For this reason, persistent nausea and vomiting from any cause should be controlled with medications, if possible.

ULCER DISEASE

A gastric ulcer is an erosion into the stomach. A peptic ulcer is an erosion into the duodenum (first portion of the small bowel) that is worsened by the constant assault from gastric acid and digestive juices. Many ulcers are caused by infection of the inner lining of the stomach and bowel with the microorganism Helicobacter pylori, which can be eradicated with an intensive course of multiple antibiotics. Such therapy is undertaken not in the field, but under the supervision of a physician.

The major symptom of ulcer disease is burning, sharp, or aching pain in the upper abdomen that is usually relieved by the ingestion of food or antacids, although the latter alone may be therapeutic. Classically, the pain occurs when the stomach is empty, particularly during times of emotional stress. Because the greatest amounts of acid are secreted following meals and between the hours of midnight and 3:00 a.m., these are times when pain is most frequent.

If the victim is strongly suspected or known to have an ulcer, and can control the pain readily with medications, the journey can continue. Make every attempt to keep on a regular meal schedule and to take medication properly during waking hours. As noted below, cigarette smoking and alcohol ingestion are strictly prohibited. If pain is not immediately controlled, or if there is any suggestion of bleeding or perforation, rapid transport to a hospital is indicated.

Therapy

1. Antacids. These are the traditional mainstay of therapy and should be taken in a dose of 2 to 3 tbsp (30 to 45 mL) 1 and 3 hours after meals, at bedtime, and as necessary to control pain. Liquids are generally more effective than tablets. Solid food and milk are not recommended as antacids. While they may decrease pain briefly, they actually stimulate the secretion of acid.

2. Drugs to inhibit the secretion of acid. Medications used to decrease acid secretion (antagonists to histamine H2 receptors [H2RAs] and proton [acid] pump inhibitors [PPIs]) decrease bowel activity and cramping.

3. Drugs to protect the lining of the gastrointestinal tract. Sucralfate (Carafate) is a drug that binds with the ulcer and protects the bowel lining from further erosion. Because it requires the presence of acid in the ulcer crater to be activated, it should not be given at the same time as antacids.

4. Avoidance of alcohol, tea, coffee, tobacco, and known gastric irritants.

5. Do not use household baking soda to neutralize acid in the stomach. Baking soda (bicarbonate) reacts with the acid to liberate heat and gas.

HEPATITIS

Hepatitis is inflammation of the liver that is caused by viral infection or parasitic infestation, drugs, toxic chemicals, alcohol abuse, or autoimmune disease. Type A infectious (short-incubation) hepatitis is the more commonly encountered viral form. The virus is excreted in urine and feces and contaminates drinking water and food products (such as raw shellfish). Type B infectious (long-incubation) hepatitis is caused by a virus found in many body fluids (blood, saliva, semen) and is spread by direct person-to-person contact. Type C infectious hepatitis (formerly non-A, non-B hepatitis) is caused by at least one virus and is most commonly associated with blood transfusions. Multiple other forms of viral hepatitis have been discovered by medical researchers.

Hepatitis causes the victim to have a constellation of signs and symptoms, which include yellow discoloration of the skin and eyes (jaundice—from the buildup of bilirubin pigment, which the diseased liver cannot process properly), nausea and vomiting, fatigue, weakness, fever, chills, darkened urine, diarrhea, pale-colored bowel movements (which may precede the onset of jaundice by 1 to 3 days), abdominal pain (particularly in the right upper quadrant over the swollen and tender liver), loss of appetite, joint pain, muscle aching, itching, and red skin rash. A young child may suffer from type A infection, yet show only a mild flu-like illness.

Anyone suspected of having hepatitis should be placed at maximum rest and transported to a physician. Avoid alcohol and medication ingestion, because the metabolism of many drugs is altered in the victim with a diseased liver. He should be encouraged to avoid dehydration and should maintain adequate food intake. If the cause of hepatitis is viral, the victim’s disease may be contagious for his first 2 weeks of illness. Do not share eating utensils or washrags. Body secretions (saliva and waste products) frequently carry the virus; therefore, pay strict attention to handwashing. Sexual contact should be avoided during the infectious period. In no case should a needle used for injection of medicine into one person be reused for another individual.

Protection against hepatitis is best accomplished by prevention of virus transmission through good hygiene. Hepatitis A vaccine is available (see page 454). In countries of high hepatitis incidence (poor sanitation, infested water or food), pooled immune serum globulin (ISG, or gamma globulin) injections are advised (see page 454); these protect unimmunized people against hepatitis A, and diminish symptoms in infected people. In a recent study that compared hepatitis A vaccine against ISG for postexposure prophylaxis against hepatitis A in persons who had not been previously immunized, it appeared that they were roughly equivalent, with the ISG being slightly more effective at preventing hepatitis A. Hepatitis B vaccine (see page 454) is intended for health care workers or those who will visit or reside in regions of high endemicity. It is of little benefit against hepatitis A.

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DISORDERS OF THE GASTROINTESTINAL TRACT

DIARRHEA

General Therapy for Diarrhea