Flexible sigmoidoscopy enables the endoscopist to look at the inside of the large bowel from the rectum through the left side of the colon, known the sigmoid or descending colon. Endoscopists may use the procedure to find the cause of diarrhoea, abdominal pain or constipation. With flexible sigmoidoscopy, the endoscopist can see bleeding, inflammation, abnormal growths and ulcers in the descending colon and rectum.
The patient lies on their left side and the endoscopist inserts a flexible, lighted tube into the rectum and carefully guides it into the colon. The scope transmits an image to a screen, so the endoscopist can examine the lining of the gut.
If anything unusual is in the rectum or colon, like a polyp or inflamed tissue, the endoscopist can remove a piece of it using instruments inserted into the endoscope. The biopsies are sent to the laboratory for testing.
Complications are uncommon: however, bleeding and damage to the colon are possible complications of sigmoidoscopy.
Flexible sigmoidoscopy usually takes 10 to 15 minutes. During the procedure, patients may feel pressure and slight cramping in the lower abdomen.