Comparison of coffee intake and coffee-induced symptoms in patients with duodenal ulcer, nonulcer dyspepsia, and normal controls. Coffee and decaffeinated coffee stimulate acid secretion. In addition, many patients experience dyspepsia after coffee ingestion. Therefore, coffee is often prohibited by physicians in patients with peptic diseases. However, the association between peptic disease and symptoms remains unclear. This study compares coffee intake and the induction of symptoms by coffee in patients with duodenal ulcer disease, nonulcer dyspepsia, and normal controls. We have studied the coffee drinking habits of 58 duodenal ulcer patients, 55 nonulcer dyspepsia patients, and 55 normal controls. The use of coffee on a daily basis was not significantly different between duodenal ulcer patients (64%) and controls (56%), or between nonulcer dyspepsia patients (55%) and controls. There was also no difference between the three groups in the use of decaffeinated coffee, the number of cups per day, the method of preparation, the length of time of coffee use, or any change in coffee intake in the previous year. The intake of tea, caffeinated carbonated beverages, and aspirin or nonsteroidal anti-inflammatory drugs was also similar in the three groups. The duodenal ulcer patients were more likely to be cigarette smokers (45%) than either the controls (16%) or the nonulcer dyspepsia patients (24%). Daily alcohol intake was not significantly different in the three groups. The prevalence of coffee induction of dyspeptic symptoms was similar in duodenal ulcer patients (29%) and controls (22%), but was much more common in nonulcer dyspepsia patients (53%) than in controls (22%), p = 0.0036. In conclusion, there was no difference in coffee intake between patients with duodenal ulcer, nonulcer dyspepsia, or normal controls. However, patients with nonulcer dyspepsia, but not duodenal ulcer, were more likely to experience dyspeptic symptoms after coffee ingestion. 