It may be caused by the stomach being in the wrong position, a foreign substance, or an abnormal joining of one part of the stomach or intestine to another. It most commonly occurs in the sigmoid colon, the ileocecal area, or the small intestines. Obstruction, pain, and distention occur quickly and, if not relieved, often result in gangrene.
Colonic distention and pain appear rapidly as a result of the obstruction. Symptoms are abdominal pain and vomiting. A volvulus of the large intestine will also cause constipation and swelling of the abdomen.
Volvulus is believed to be due to a redundant sigmoid colon or a mobile ascending colon, and may be precipitated by an unusual amount of residue in the involved portion of the bowel. If this obstruction is not relieved within a few hours, gangrene will set in. The twist may be only I80 degrees and gangrene may not occur immediately, or the twist may be 360 degrees, in which case gangrene is a certainty. Spontaneous reduction or relief occasionally occurs but its duration is only temporary.
A confirmatory X-ray of the abdomen shows the closed-loop type of obstruction. In the case of a sigmoid volvulus there is a classical picture on barium enema X-ray that includes a “bird’s-beak” appearance or sign, whereby the proximal rectum narrows down toward the point of the obstruction, thus creating a beaklike projection. See the X-ray below:
Abdominal x-ray of dilated colon. Barium fills the rectum to the rectosigmoid. Note the “beak-like” appearance of the rectosigmoid, which is typical of a sigmoid volvulus.
If the twist is incomplete, spontaneous reduction may occur, or may be induced by insertion of a rectal tube via the sigmoidoscope. However, if relief does not occur promptly, valuable time should not be lost by persisting with such conservative measures. In most cases, an abdominal operation is needed to untwist the volvulus. If part of the intestine becomes damaged or gangrenous, then that part of the intestine should be removed. Abdominal surgery with reduction of the volvulus, and either immediate or delayed anastomosis, should be performed.