Studies on small intestinal obstruction. I. Intraluminal pressure in experimental low small bowel obstruction in the cat.

Intra-intestinal pressure was recorded with open-tip catheters in experimental low small-bowel obstruction in the cat. At zero time the pressure was 2-4 mmHg. After 72 hours sustained intraluminal pressure ranged mainly between 5 and 10 mmHg. Long periods of inactivity alternated with short bouts of spontaneous bowel activity. During activity the pressure rose to about 20 mmHg. In motility responses elicited by cholecystokinin, momentary pressure waves amounting to 40-50 mmHg were recorded. The result of simple mechanical obstruction is predominantly a bowel distension, whereas the magnitude of sustained intraluminal pressure is rather modest. Possible effects of distension on intestinal microcirculation are discussed.