During the last two years one of us has encountered ten diabetic patients with either continuous and uncontrollable diarrhea, or attacks of diarrhea. An analysis of the gastric secretion by the fractional method revealed an achlorhydria in each case. The relationship between the absence of free hydrochloric acid in the gastric contents and a certain type of diarrhea as originally described by Einhorn,1who termed it "gastrogenic," is well known. With the advent of the roentgen ray it was possible to study the gastric motility in these cases, and it was noted that the stomach was atonic and emptied rapidly, thus causing a rush of inadequately chymified food into the duodenum. It is the experience of many observers that the diarrhea, in a large percentage of these cases, diminishes or stops with the administration of dilute hydrochloric acid by mouth, even though the administration of the acid does not in