Effect of cigarette smoking on competence of the pylorus: preliminary study.

The competence of the pylorus was studied in 13 normal volunteers and nine dyspeptic patients by means of a radiological technique involving intubation of the duodenum. The pylorus was found to be competent in most normal individuals and in fewer than half of the dyspeptic patients. However, on smoking a cigarette, appreciable increase in duodenogastric reflux was seen in nine out of the 13 normal volunteers and in seven out of the nine dyspeptic patients. Such induced pyloric incompetence and the resultant regurgitation of duodenal juices may explain the increased incidence of gastritis and gastric ulceration in heavy smokers.