A washout technic with intestinal infusion of an inert gas mixture was used to study the relation of gas to functional abdominal symptoms. The volume of gas in the intestinal tract (176 ± 28 ml S.E.M.) of 12 fasting patients with chronic complaints of excess gas did not differ significantly (P > 0.10) from that of 10 controls (199 ± 31 ml). Similarly, there was no difference in the composition or accumulation rate of intestinal gas. However, more gas tended to reflux back into the stomach in patients who complained of abdominal pain during infusion of volumes of gas well tolerated by controls. Six patients with severe pain during the study had intestinal transit times of gas (40 ±6 minutes S.E.M.) that were significantly (P <0.05) longer than those of the control group (22 ± 3 minutes). Thus, complaints of bloating, pain and gas may result from disordered intestinal motility in combination with an abnormal pain response to gut distention rather than from increased volumes of gas. (N Engl J Med 293:524–526, 1975). “TOO much gas” causing abdominal pain and bloating is probably the most common gastrointestinal complaint encountered in medical practice. An unusual feature of this complaint is that the patient provides the physician not only with his symptoms but with a quantitative assessment of the pathophysiologic abnormality responsible for them. Lacking adequate objective measures of abdominal gas volumes, medical science has generally accepted the patient's subjective assessment of his quantity of intestinal gas. Thus, the concept is widespread that excessive gas is a frequent cause of functional abdominal symptoms, although objective data to substantiate this relation are not available. In the.