A bezoar is an accumulation of unabsorbed, undigested matter in the digestive tract that hardens and coalesces to form a solid mass. Typically, this occurs in the stomach with extension into the duodenum, but a bezoar can involve any part of the gastrointestinal tract. It can be composed of different materials, commonly seeds, fiber, vegetable matter (phytobezoar), hair (trichobezoar), or medications (pharmacobezoar). Bezoars are associated with trichotillomania and other psychiatric disorders, pica, dehydration, opiate or anticholinergic use, and impaired gastric motility. Additionally, children with autism or developmental delay may be at increased risk.

A bezoar may be asymptomatic or cause symptoms due to partial or complete gastric obstruction. These symptoms include epigastric pain, anorexia, early satiety, nausea, or emesis. A palpable abdominal mass may be present in some cases.

Related topic: small bowel obstruction