The sigmoid colon is the last section of the the large intestine. Two anatomic differences can increase the risk of sigmoid volvulus. One is an elongated or movable sigmoid colon that is unattached to the left sidewall of the abdomen. Another is a narrow mesentery that allows twisting at its base. Sigmoid volvulus, however, can occur even without an anatomic abnormality.
Risk Factors
Risk factors that can make a person more likely to have sigmoid volvulus are Hirschsprung's disease, intestinal pseudo-obstructions, and megacolon (an enlarged colon). Adults, children, and infants can all have sigmoid volvulus. It is more common in men than in women, possibly because men have longer sigmoid colons. It is also more common in people over age 60, in African Americans, and in institutionalized individuals who are on medications for psychiatric disorders. In addition, children with malrotation are more likely to get sigmoid volvulus.
Symptoms
The symptoms can be acute (occur suddenly) and severe. They include a bowel obstruction (commonly seen in infants), nausea, vomiting, bloody stools, abdominal pain, constipation, and shock. Other symptoms can develop more slowly but increase over time, such as severe constipation, lack of passing gas, crampy abdominal pain, and abdominal distention. A doctor may also hear increased or decreased bowel sounds.
Tests and Diagnosis
Several tests are used to diagnose sigmoid volvulus. X rays show a dilated colon above the volvulus. Upper and lower GI series help locate the point of obstruction and show whether malrotation of the rest of the colon is present. A CT scan may be used to show the degree of twisting and malrotation, and whether perforation has occurred.
In most instances, a sigmoidoscope, a tube used to look into the sigmoid colon and rectum, can be used to reach the site, untwist the colon, and release the obstruction. However, if the colon is found to be twisted very tightly or is twisted so tightly that blood flow is cut off and the tissue is dead, immediate surgery will be needed to correct the problem and, if possible, restore the blood supply. Dead tissue will be removed during surgery, and a portion of the colon may be removed as well—a procedure called a resection. Sigmoid volvulus can recur after untwisting with the sigmoidoscope, but resection eliminates the chance of recurrence.
Prompt diagnosis of sigmoid volvulus and appropriate treatment generally lead to a good outcome.
Topics:
Information provided by the National Digestive Diseases Information Clearinghouse. National Institute of Diabetes and Digestive and Kidney Diseases. National Institutes of Health. NIH Publication No. 05–5120, February 2005. Downloaded December 7, 2007 from http://digestive.niddk.nih.gov/ddiseases/pubs/anatomiccolon/index.htm
Page Last Revised: August 26, 2011
Risk Factors
Risk factors that can make a person more likely to have sigmoid volvulus are Hirschsprung's disease, intestinal pseudo-obstructions, and megacolon (an enlarged colon). Adults, children, and infants can all have sigmoid volvulus. It is more common in men than in women, possibly because men have longer sigmoid colons. It is also more common in people over age 60, in African Americans, and in institutionalized individuals who are on medications for psychiatric disorders. In addition, children with malrotation are more likely to get sigmoid volvulus.
Symptoms
The symptoms can be acute (occur suddenly) and severe. They include a bowel obstruction (commonly seen in infants), nausea, vomiting, bloody stools, abdominal pain, constipation, and shock. Other symptoms can develop more slowly but increase over time, such as severe constipation, lack of passing gas, crampy abdominal pain, and abdominal distention. A doctor may also hear increased or decreased bowel sounds.
Tests and Diagnosis
Several tests are used to diagnose sigmoid volvulus. X rays show a dilated colon above the volvulus. Upper and lower GI series help locate the point of obstruction and show whether malrotation of the rest of the colon is present. A CT scan may be used to show the degree of twisting and malrotation, and whether perforation has occurred.
In most instances, a sigmoidoscope, a tube used to look into the sigmoid colon and rectum, can be used to reach the site, untwist the colon, and release the obstruction. However, if the colon is found to be twisted very tightly or is twisted so tightly that blood flow is cut off and the tissue is dead, immediate surgery will be needed to correct the problem and, if possible, restore the blood supply. Dead tissue will be removed during surgery, and a portion of the colon may be removed as well—a procedure called a resection. Sigmoid volvulus can recur after untwisting with the sigmoidoscope, but resection eliminates the chance of recurrence.
Prompt diagnosis of sigmoid volvulus and appropriate treatment generally lead to a good outcome.
Topics:
A. Anatomy of the Colon
B. Anatomic Problems of the Colon1. Malrotation and Volvulus
2. Small Bowel and Colonic Intussusception
3. Fistulas
4. Colonic Atresia
5. Sigmoid Volvulus
6. Cecal Volvulus
7. Imperforate Anus (Anal Atresia)
Information provided by the National Digestive Diseases Information Clearinghouse. National Institute of Diabetes and Digestive and Kidney Diseases. National Institutes of Health. NIH Publication No. 05–5120, February 2005. Downloaded December 7, 2007 from http://digestive.niddk.nih.gov/ddiseases/pubs/anatomiccolon/index.htm
Page Last Revised: August 26, 2011
