<prompt> Sigmoid valvulus rotations occursClockwiseAnticlockwiseBoth clockwise and anticlockwiseAxial in direction  <response>: Anticlockwise 1197-LB 1192-B L 25thSIGMOID-VOLVULUS - Most common cause of large bowel obstruction in indigenous black Africans Rotation nearly always occurs in an anticlockwise direction Predisposing factors include high-residue diet and chronic constipation Predisposing causes - 1 Band of adhesions peridiverticulitis Overloaded pelvic colon, Long pelvic mesocolon, narrow attachment of pelvic mesocolon Plain film of abdomen - The distended loop may assume a coffee bean shape In caecal Volvulus the concavity of the coffee bean points towards the right lower abdominal quadrants, and in sigmoid Volvulus it points towards the left lower quadrant. On barium enema a birds beak or ace of spades deformity with spiral narrowing of the upper end of the lower segment is pathognomic. Between attacks barium enema may reveal sigmoid megacolon - 739CSDT l1th 