Digestive Health Inflammatory Bowel Disease Diagnosis Sigmoidoscopy Overview: Uses, Procedure, Risks By Amber J. Tresca facebook twitter linkedin Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16. Learn about our editorial process Amber J. Tresca Medically reviewed by Medically reviewed by Priyanka Chugh, MD on December 06, 2019 linkedin Priyanka Chugh, MD, is a board-certified gastroenterologist in practice with Trinity Health of New England in Waterbury, Connecticut. Learn about our Medical Review Board Priyanka Chugh, MD on December 06, 2019 Print A sigmoidoscopy is a way for a doctor to examine the last one-third of the large intestine, which includes the rectum and sigmoid colon. A flexible viewing tube with a lens and light source on the end, called a sigmoidoscope, is inserted through the anus and into the rectum. Looking through the eyepiece at the other end of the scope, the doctor can see the inside of the colon. John Fedele / Getty Images In this test, the doctor can check for cancer, abnormal growths (polyps), and ulcers. Most of the time, a sigmoidoscopy is done in the office of a gastroenterologist or a colorectal surgeon. There may or may not be a preparation, depending on the preference of the doctor and the reason for the test. It can be uncomfortable because there is no sedation, but most physicians keep the test very quick in order to cut down on patient discomfort. If there is prep and sedation is used, the test might take longer. Uses Beginning at age 50, a sigmoidoscopy may be recommended every 3 to 5 years to screen for colorectal cancer. In people who are at a higher risk for colorectal cancer due to inflammatory bowel disease (especially ulcerative colitis), family history of colorectal cancer, or familial polyposis, screening may be recommended starting at age 35. A sigmoidoscopy may also be used as a follow-up procedure after a digital rectal exam is abnormal, or after a positive fecal occult blood test. It can also help identify the source of some types of rectal bleeding or other problems in the lower digestive tract. A biopsy may be taken during the procedure if the doctor deems it necessary. If an abnormality is found in a sigmoidoscopy, a colonoscopy may be recommended. Preparation In order for the doctor to get a clear view of the intestinal wall, the colon must be fairly empty. The doctor will give you specific instructions on how to prepare for the test, which may include laxatives or enemas. On the day of the test, your diet should consist mainly of liquids rather than solid food. Procedure You may be asked to wear a hospital gown or to remove your clothes from the waist down. An assistant may record temperature, pulse, blood pressure, and respiratory rate. You will be instructed to lie on your left side on the exam table, with one or both knees raised to your chest. The doctor will insert the sigmoidoscope into your rectum and pump air through the sigmoidoscope if necessary for a clearer view. A biopsy may be taken using a device at the end of the sigmoidoscope. A biopsy is a piece of tissue that can be sent to a lab for further analysis under a microscope. Risks Injury to the bowel is a very rare complication of this procedure. Follow-Up If a biopsy was taken, your doctor should have the results in a few days. A normal diet and schedule can be resumed immediately after the test. When to Call the Doctor Call your doctor immediately if you experience: Rectal bleeding Feeling faint Short of breath Palpitations Call your doctor if you experience: Nausea Vomiting Cramps Abdominal pain Fever Chills Severe headache Muscle aches A Word From Verywell A sigmoidoscopy is limited to screening only the lower one-third of the bowel. For a complete screening for colorectal cancer, a colonoscopy is necessary to screen for cancer or polyps higher in the bowel. Was this page helpful? Thanks for your feedback! We're providing tips on how to take better care of your gut. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Cancer Society. "Frequently Asked Questions About Colonoscopy and Sigmoidoscopy." Cancer.org. Feb 2 2016.