When the ascending colon fails to be fixed into the right abdomen, excessive mobility may occur which can allow for torsion and displacement of the ascending colon into the left upper quadrant. The term cecal volvulus is somewhat of a misnomer since the point of torsion is usually well above the ileocecal valve. This abnormality represents approximately 1 to 3% of cases of intestinal obstruction in adults and may occur as a sudden abdominal emergency. Mobility of the cecum is not uncommon in asymptomatic patients, which suggests that for torsion to occur there should be an underlying precipitating condition. In approximately one-third of cases there will be evidence of an obstruction distal to the torsion.

There are two types of torsion of the ascending colon. Axial torsion is more common and may be from 180 to 360 degrees along the longitudinal axis of the colon. Plain film findings suggestive of cecal volvulus can be seen in the majority of patients. The cecum is disproportionately distended and occupies the central abdomen or left upper quadrant. Haustrations usually are preserved. The small bowel may be lateral to the cecum. Three quarters of patients have air fluid levels in the cecum. Barium enema examination demonstrates a "beak" at the point of torsion similar to that seen with a sigmoid volvulus.

Cecal bascule is a less common cause for cecal and ascending colon distension. In this condition, the cecum folds anteriorly and medially in front of the ascending colon causing a flap valve occlusion at the site of flexion. A barium enema may show barium entering the cecum and may reduce the distended colon. A precipitating factor for formation of the cecal bascule is adhesive bands across the ascending colon.

In the classic case, the differential diagnosis is limited to axial torsion or a cecal bascule. Other segments of colon may be dilated and mimic a distended cecum. Diffuse colonic ileus, Ogilvie's syndrome, will show colonic dilatation distally either to the level of the splenic flexure or beyond. When the small bowel is markedly dilated, the diagnosis of cecal volvulus may be obscured.