Existence of a high pressure zone at the rectosigmoid junction in normal Indian men

A hypertonic, electrically hyperactive segment has been described in the rectosigmoid region mainly in constipated persons. Anatomic or manometric evidence to satisfy the criteria for a sphincter here is, however, inconclusive. We evaluated the pressure profile of the rectosigmoid region in normal Indian men.

Fifteen male volunteers with regular bowel habits were studied. Rectosigmoid manometry (1 cm station pull-through) was done in the fasting state using a water-perfused system and three-lumen catheter with radially oriented recording ports 5 cm apart.

Eight volunteers had a zone of high pressure. Proximal extent of this zone was identified as the station with a rise in basal pressure of at least 10 mmHg over the previous station. A further rise of at least 10 mmHg in subsequent distal stations was considered essential for defining the existence of the zone. This zone had a median length of 3 cm, with midpoint at median 18 cm from the anal verge and median highest pressure of 36 mmHg. There was no antegrade pressure gradient across the zone; rectal pressures were higher than those in the sigmoid in 12 of 15 volunteers.

Approximately one-half of normal Indian men with regular bowel habits have a high pressure zone in the rectosigmoid region. The role of diet or defecation posture in its etiology and its effect on bowel habit need to be studied.