Brown bowel syndrome is the name applied to a brown discoloration of the intestine. This is due to lipofuscin deposition in intestinal smooth muscle and occurs in association with malabsorption. Three cases occurring in a coeliac registry of 559 patients are described. One patient presented with acute massive bleeding per rectum, and two were diagnosed at autopsy. The syndrome may be accompanied by vitamin E deficiency and neurologic dysfunction. Two patients had evidence of peripheral neuropathy, and one had low vitamin E levels. Concomitant vitamin D deficiency was present. Fat-soluble vitamin malabsorption, especially if there is a poor response to a gluten-free diet or neuropathy, might alert the clinician to the possibility of brown-bowel syndrome and suggests careful search for lipofuscin in biopsy material, using special histologic techniques.