The condition of lymphoid hyperplasia is often a normal finding in children. It is thought by some authors that lymphoid hyperplasia might act as a nidus for childhood idiopathic ileocolic intussusception. The pattern has also been described in patients with immunodeficiency, giardiasis infestation, Yersinia infections of the small bowel (usually the terminal ileum), Whipple’s disease, and Waldenström’s macroglobulinemia. Some investigators believe there is an association of lymphoid hyperplasia of the terminal ileum with the development of Crohn’s disease in the distal small bowel. These nodules can range in size from 2 to 5 mm and usually involve the distal small bowel (see figure). Crossover into the colon is unusual, although colonic lymphoid hyperplasia is a known entity. In most cases, these nodules are regarded as a reactive hyperplasia secondary to bowel response to a viral infectious or inflammatory process that is generally self-limiting and eventually disappears.

It is thought that in some cases nodular lymphoid hyperplasia may be a presenting sign of small bowel multifocal lymphoma. Another unusual association that has been reported is lactose intolerance. In some instances in adults, the condition has been pronounced and symptomatic with weight loss, diarrhea, and abdominal pain to the point at which resection of the terminal ileum was undertaken with varying results.