Neither the natural history of gastrointestinal symptoms in patients with anorexia nervosa nor their response to refeeding have been well studied. We hypothesized that gastrointestinal symptoms in anorexia nervosa will decrease during refeeding despite high caloric intake, suggesting that delayed gastric emptying, where present, is a result rather than a cause of anorexia nervosa. Study goals were (a) to determine the type and frequency of gastrointestinal symptoms, (b) to follow symptoms during refeeding prospectively, and (c) to develop guidelines for gastrointestinal testing and intervention in hospitalized anorectic patients. Sixteen consecutive patients with anorexia nervosa were rated on 12 gastrointestinal symptoms before and after nutritional rehabilitation and followed up throughout treatment. All patients reported multiple gastrointestinal symptoms on admission; all symptoms except belching improved during treatment despite large calorie increases (p less than 0.0002); significant improvements occurred in appetite, bloating, constipation, vomiting, and diarrhea; and no patients required endoscopy, x-ray evaluation, or antipeptic regimens. We conclude that although severe gastrointestinal symptoms are common in anorexia nervosa, they improve significantly with refeeding. Specific gastrointestinal studies should be reserved for patients who do not gain weight or who have indications of independent digestive disease.