Case Presentation:

A 64‐year‐old woman presented with diarrhea, 100‐pound weight loss, and occasional abdominal discomfort ongoing for 6 months prior to presentation. She endorsed profuse watery, green, foul‐smelling diarrhea as frequently as 6–8 times per day, diffuse cramping abdominal discomfort, and worsened symptoms with oral intake. She had been hospitalized 5 times over the preceding several months for dehydration related to her symptoms. She had previously undergone an extensive and unrevealing evaluation, including esophagogastroduodenoscopy (EGD), colonoscopy, sigmoidoscopy, CT scan, and trial of antibiotics as well as lactose‐free and gluten‐free diets without improvement of her diarrhea. She had also briefly been tried on Asacol as an outpatient for an empiric diagnosis of “colitis,” but this led to a rash and also did not improve her symptoms. Prior EGD was remarkable only for H. pylori, and she completed eradication therapy. Laboratory evaluation was largely unremarkable, including normal a complete blood count and comprehensive metabolic panel. A stool ova and parasites culture, fecal fat assay, Shiga‐like toxin, stool occult blood, and C. difficile assay were negative, and serologies for celiac disease were negative. She subsequently underwent repeat EGD in our institution, which showed intense active chronic enteritis with loss of goblet cells and Paneth cells, corroborating a diagnosis of autoimmune enteritis. A repeat colonoscopy showed mild degenerative changes and increased intraepithelial lymphocytes consistent with a milder form of autoimmune enteritis. She was treated with a tapering dose of prednisone and transitioned to therapy on Imuran, and she subsequently gained weight, and her symptoms significantly improved.

Discussion:

Autoimmune enteritis is a cause of diarrhea and malabsorption described more commonly in infancy and rarely reported in adult patients. This pathologic entity is characterized by protracted diarrhea and malabsorption with atrophy of the small intestine mucosa associated with circulating autoantibodies to gut enterocytes. Gluten enteropathy is the diagnosis most frequently invoked in the adult patient to explain a syndrome comprising diarrhea, malabsorption, and villous atrophy. This case demonstrates the importance of considering a diagnosis of autoimmune enteritis in such patients in whom testing for celiac disease is negative. Some authors have recommended testing for enteroctye autoantibodies in all patients with refractory sprue, as well as all patients presenting with upper and lower intestinal symptoms eluding diagnosis.

Conclusions:

Autoimmune enteritis is a rare cause of diarrhea and malabsorption associated with villous atrophy in the presence of circulating antienterocyte antibodies. Hospitalists should be aware of this clinical entity and consider it in the appropriate clinical circumstance.

Disclosures:

W. T. Repaskey ‐ University of Michigan, none.