BACKGROUND: Patients complaining of abdominal bloating have impaired tolerance and clearance of intestinal gas loads. Mild exercise enhances intestinal clearance and prevents retention of intestinal gas loads in healthy subjects. Our aim was to evaluate the putative beneficial effects of physical activity in patients with abdominal bloating. METHODS: In eight patients complaining of bloating, seven with irritable bowel syndrome, and one with functional bloating, according to Rome II criteria, a gas mixture was continuously infused (12 mL/min) into the jejunum for 120 min with simultaneous duodenal lipid perfusion (1 kcal/min). Gas evacuation, perception (0-6 scale), and abdominal girth were measured at 15-min intervals. Paired studies were randomly performed in the supine position during intermittent pedaling (5 min with 3-min rest intervals at 40 rpm and 0.15 kp load) versus rest (as control). RESULTS: During rest, a significant proportion of the gas infused was retained in the gut (45 ± 9%, P < 0.01 vs basal), but retention was significantly lower during exercise (24 ± 7%, P < 0.05 vs rest). Gas retention during rest was associated with significant abdominal symptoms (3.6 score; P < 0.01 vs basal), and symptoms also improved during exercise (2.8 score, P < 0.05 vs rest). During the test, patients developed abdominal distension, which was related to the volume of gas retained (r = 0.68, P < 0.05). CONCLUSION: Mild physical activity enhances intestinal gas clearance and reduces symptoms in patients complaining of abdominal bloating. © 2006 by Am. Coll. of Gastroenterology.