Flexible sigmoidoscopy enables the physician to look at the inside of the sigmoid or descending colon, the lower one third of the colon. Your doctor may use the procedure to find the cause of diarrhea, abdominal pain, or constipation. It is also used to look for early signs of cancer in the descending colon and rectum. With flexible sigmoidoscopy, the physician can see bleeding, inflammation, abnormal growths, and ulcers in the descending colon and rectum. To view the upper two-thirds of the colon a colonoscopy is required.
During the procedure, the physician inserts a short, flexible, lighted tube into your rectum and slowly guides it into your colon. The scope transmits an image of the inside of the rectum and colon, so the physician can carefully examine the lining of these organs. The scope also blows air into the area to help the physician to see more clearly. If anything unusual is in your rectum or colon, like a polyp or inflamed tissue, the physician can remove a piece of it using instruments inserted into the scope. The physician will send that piece of tissue (biopsy) to the lab for testing.
Bleeding and puncture of the colon are possible complications of sigmoidoscopy. However, such complications are uncommon.
Flexible sigmoidoscopy takes 10 to 20 minutes. During the procedure, you might feel pressure and slight cramping in your lower abdomen. Patients report continued gas pain until the air leaves the colon. Walking helps alleviate the gas, but it is important to follow your doctor’s orders.