A flexible sigmoidoscopy is a medical procedure that involves sending a small camera attached to a special tube up through anus into the rectum and lower colon to look for possible abnormalities. It may be used as a diagnostic test if someone is having symptoms of possible gastrointestinal problems, or as a screening test for colon cancer. Patients often need to follow certain instructions to prepare for a flexible sigmoidoscopy. In general, the procedure itself takes just a short time to complete and can be done in a hospital or other health-care facility on an out-patient basis.
The sigmoid colon represents approximately the last 2 feet (0.6 meters) of large intestine before it turns into the rectum and anus. A flexible sigmoidoscopy is able to look at inside of this portion of the colon, as well as the rectum and anus, via a small video camera attached to the top of a long, thin tube, which is in turn attached to a video monitor. The tube is inserted through the anus and air is pumped in to help expand the colon for optimal viewing. Also attached to the tube is a small cutting tool that allows a health-care provider to take tissue samples from inside the colon and rectum, if necessary.
People may undergo flexible sigmoidoscopy if they have digestive symptoms that indicate a possible problem in the lower large intestine. Such symptoms may include recurrent constipation or diarrhea, stomach pain, and bleeding from the anus. Tissue samples may be removed during the procedure to test for infections. The test may also be used to help screen for colon cancer, which is generally recommended for most adults over age 50, as it allows a health-care provider to view polyps and other potentially cancerous or precancerous lesions inside the lower intestine. If any such areas are seen, tissue samples may be removed for further testing.
To prepare for a flexible sigmoidoscopy, a patient is usually given enemas a few hours before the procedure is set to begin. An enema helps flush out any fecal material from the lower intestine. In some cases, patients may need to fast and/or take laxatives starting a couple of days before the procedure to help clear out the full intestine, not just the lower portion.
A flexible sigmoidoscopy is generally performed in a hospital or other health-care facility. It is generally a fairly short procedure, usually taking about 15-20 minutes from the time the scope is inserted until the time it is removed. Patients may need to be in the facility for a longer period, though, to complete any preparatory steps and to be monitored briefly after the procedure is completed.
In general, patients are not given sedation, so they may return to their usual activities shortly after the procedure. Possible short-term side effects may include cramping and gas, due to the air pumped into the intestine, or a small amount of rectal bleeding if any biopsies were taken. Complications of flexible sigmoidoscopy are rare, but may include perforation of the colon. This can be a life-threatening condition and usually requires surgery to repair.