Food Hypersensitivity as a Cause of Rectal Bleeding in Adults

Background & Aims Rectal bleeding and lymphonodular hyperplasia (LNH) in children can be caused by food hypersensitivity (FH). Our aim was to verify whether similar clinical and endoscopy presentations in adults can be due to FH. Methods Consecutive adult patients with rectal bleeding were enrolled. All underwent routine assays, colonoscopy, and histology study. Results Ten of 64 (15%) patients showed LNH as the unique sign at colonoscopy. An oligoantigenic diet resolved the rectal bleeding in 9 patients, and the reintroduction of several foods caused symptom reappearance. Double-blind placebo-controlled challenges with cow's milk and wheat protein confirmed the FH; symptoms reappeared 1–96 hours after the challenge. None of the patients were positive for IgE-mediated assays. In patients with LNH and FH, histology of the ileum and colon mucosa showed a higher number of lymphoid follicles and intraepithelial and lamina propria eosinophils compared with the other patients with rectal bleeding. Conclusions Recurrent rectal bleeding can be caused by FH in adult patients. Endoscopic evidence of LNH characterizes these cases.