Dr. Bader Faiyaz Zuberi
Consultant Gastroenterogist & Hepatologist, Assistant Professor
Dow University of Health Sciences, Karachi, Pakistan

Flexible sigmoidoscopy is an endoscopic procedure that allows examination of the rectum and lower part of the colon. The examination takes approximately 10–20 minutes and may be performed in a physician’s office, a procedure room, or in a hospital. Sigmoidoscopy is well tolerated with minimal discomfort.
Preparation for a thorough and safe sigmoidoscopy may include a clear liquid diet followed by an enema or liquid solution to clear the colon and rectum. Often all that is necessary is 1–2 enemas just prior to the procedure. This preparation is dependent upon the discretion of the physician. Most medications may be taken as prescribed. However, continuation of aspirin, non-steroidal anti-inflammatory drugs, and blood thinners should be discussed with the physician at the time of scheduling or a week prior to the procedure.

The sigmoidoscope is a short, flexible, lighted tube that transmits images of the inside of the colon and rectum to an eyepiece or a video monitor to enable examination of the organ linings (Figure 1, A-C). Biopsy specimens (samples of the tissue) may be taken through an accessory channel of the scope for later laboratory analysis. This is a painless procedure.

Flexible sigmoidoscopy is relatively simple to perform. The patient is usually awake and positioned on his/her left side on an examining table. The physician gently inserts a lubricated sigmoidoscope into the rectum and slowly guides it to the colon (Figure 2). Air may be introduced into the colon to improve visibility. Patients may experience slight cramping or pressure in the lower abdomen; however, as soon as air leaves the colon the discomfort resolves.

Flexible sigmoidoscopy is safe and effective when performed by professionals with appropriate training and experience. Complications are rare with fewer than 1:10,000 procedures. Complications may include bleeding from a biopsy site or perforation (a tear in the bowel wall). Symptoms of abdominal pain, distention, nausea, vomiting, chills, fever or rectal bleeding should be reported to the physician.