Flatulence is one of the commonest symptoms complained of by patients with indigestion or what they think is indigestion. Unfortunately, in many cases the cause cannot be determined. The first thing the physician must do when a patient complains of gas is to find out what he means. Does he mean that he is belching, does he bloat, does he feel as if gas was trapped in a segment of intestine or does he pass excessive amounts of flatus? Curiously a patient may have any or all of these troubles and still not have real flatulent indigestion! The chronic belcher is swallowing air because he is nervous or frightened; the woman who bloats may have only an angioneurotic edema of her bowel; the man who feels as if he had gas in his stomach may have only a duodenal ulcer or constipation, and the man who is passing much flatus