A flexible sigmoidoscopy examines the lower section of the colon — the last section of the bowel that connects to the rectum. The sigmoid colon contains a lot of muscle tissues and functions as a holding chamber for waste before it is excreted from the body.
A sigmoidocope is the device used to perform a sidmoidosopy. It is a thin, flexible tube with a small camera at the tip to capture video images, allowing the doctor to visualize the inside of the rectum, sigmoid colon, and the descending colon. The doctor may also take a biopsy — cut away a small piece of tissue for testing — during this exam.
Who Needs a Sigmoidoscopy?
Doctors perform sigmoidoscopies for many reasons. A sigmoidoscopy can evaluate or diagnose ulcers, polyps, tumors, and strictures in the lower color. It is also an investigative tool used to find the cause of many symptoms, including bloody or mucousy stools, unexplained weight loss, lower abdominal pain, changes in bowel habits, and low blood counts.
What is Diagnosed?
Doctors use flexible sigmoidoscopies to diagnose a number of conditions, including colon cancer, colon polyps, ulcerative colitis, Crohn’s disease, and rectal ulcers. A doctor may also perform a sigmoidoscopy to evaluate the progression of these conditions or how well they are responding to treatment. A doctor may also perform an exploratory sigmoidoscopy in an attempt to find the cause of the patient’s symptoms.
Sigmoidoscopy vs. Colonoscopy
Sigmoidoscopies and colonoscopies are similar, but there are differences between the two. Sigmoidoscopies are less invasive and do not require anesthesia. Both are screening tools for colon cancer, but a colonoscopy allows the doctor to examine the entire colon rather than only the lower portion. If a sigmoidoscopy locates polyps, a colonoscopy is often the next step.
Some people should not get a sigmoidoscopy. Women who are pregnant or think they may be pregnant and anyone with a bleeding disorder should discuss these issues with their doctor. The doctor should also know about any medication sensitivities or allergies and any prescription blood thinners or herbal supplements the patient takes.
Preparing for the Procedure
When getting a sigmoidoscopy, it is essential to follow the doctor’s orders to prepare. The stomach and intestines must be empty before the procedure. People scheduled for a sigmoidoscopy are sometimes required to follow a clear liquid diet up to 24 hours before the exam and use a prescribed bowel prep, enema, or laxative.
During the Procedure
During the procedure, the patient wears a hospital gown and lies on their left side on the exam table with their knees pulled up to the abdomen. The doctor inserts the sigmoidoscopy through the rectum and into the sigmoid colon. This procedure takes anywhere from 15 to 30 minutes, but it may be longer if the doctor takes biopsies.
After the Procedure
Recovery from a sigmoidoscopy is relatively fast. The patient may have to sit or lie down for a few minutes before getting up from the table. They can resume a normal diet and activities after the procedure unless the doctor says otherwise. Passing a lot of gas is normal after a sigmoidoscopy because the process introduces air into the intestine.
The doctor may be able to tell the patient some of the results following the exam, but this can take a few days, especially if waiting for biopsy results. Results are negative or positive. A negative result is when the doctor finds nothing abnormal in the lower colon. If the result is positive, the exam found polyps or other abnormal tissue and will likely order additional testing.
Risks and Complications
The most common complications of sigmoidoscopy are bleeding and perforation. Most often, these occur in patients who have had polyps removed during the exam. A perforation may need emergency surgery to repair. Delayed bleeding may also develop up to two weeks after the exam. Anyone who has recently undergone the procedure should report symptoms like fever, severe abdominal pain, and bloody stools to the doctor immediately.