[Intestinal transit time in bilio-pancreatic bypass]

Transit times were evaluated in 23 obese subjects before and 1,4 and 12 months after biliopancreatic by-pass. A modified version of the method of Hinton et al. was used to determine emptying of the stomach and partial and total transit times. Emptying of the stomach was normal preoperatively. After surgery, it was almost immediate, except in two subjects with stomitis. Both transit times were virtually unchanged. Since the segment between the stomach and the ileocaecal valve is only half as long as in the normal subject, the results show that the by-pass leads to a slowing of transit that concerns the small intestine only, is quickly established, and does not change in the course of time. Evaluation of the altered anatomical and functional situation, and the absence of a correlation between the long-term behaviour of transit times on one hand and of lipid malabsorption and weight loss on the other-hand, suggest that a slower transit time must not be regarded as a compensation mechanism, except insofar as it restricts the degree of malabsorption set up immediately after surgery. Preliminary studies of enterohormonal changes following the by-pass indicate that increased glucagon and decreased motiline values are mainly responsible for slower transit times.