Colonoscopy is performed for bleeding, blood seen on fecal occult stool test, anemia, colon cancer screening/polyp removal, diarrhea, change in bowel habits, family history of polyps or colon cancer, to diagnose or assess Inflammatory bowel disease (Crohn’s and Ulcerative colitis). The procedure is performed by Board certified Gastroenterologists. The procedure takes 25-30 minutes during which patients are sedated and monitored by an anesthesiologist. Patients are awake soon after and result are discussed/treatment is planned. Click here for preparation instructions
What is colonoscopy?
Colonoscopy is a procedure used to see inside the colon and rectum. Colonoscopy can detect inflamed tissue, ulcers, and abnormal growths. The procedure is used to look for early signs of colorectal cancer and can help doctors diagnose unexplained changes in bowel habits, abdominal pain, bleeding from the anus, and weight loss.
What are the colon and rectum?
The colon and rectum are the two main parts of the large intestine. Although the colon is only one part of the large intestine, because most of the large intestine consists of colon, the two terms are often used interchangeably. The large intestine is also sometimes called the large bowel.
The colon and rectum are the two main parts of the large intestine.
Digestive waste enters the colon from the small intestine as a semisolid. As waste moves toward the anus, the colon removes moisture and forms stool. The rectum is about 6 inches long and connects the colon to the anus. Stool leaves the body through the anus. Muscles and nerves in the rectum and anus control bowel movements.
How to Prepare for Colonoscopy
The doctor usually provides written instructions about how to prepare for colonoscopy. The process is called a bowel prep. Generally, all solids must be emptied from the gastrointestinal tract by following a clear liquid diet for 1 day before the procedure. Patients should not drink beverages containing red or purple dye. Acceptable liquids include
- fat-free bouillon or broth
- strained fruit juice
- plain coffee
- plain tea
- sports drinks, such as Gatorade
A laxative is required the night before colonoscopy. A laxative is medicine that loosens stool and increases bowel movements. Laxatives are usually swallowed in pill form or as a powder dissolved in water.
Patients should inform the doctor of all medical conditions and any medications, vitamins, or supplements taken regularly, including
- arthritis medications
- blood thinners
- diabetes medications
- vitamins that contain iron
Driving is not permitted on the day of colonoscopy to allow the sedative time to wear off. Before the appointment, patients should make plans for a ride home.
How is colonoscopy performed?
Examination of the Large Intestine
During colonoscopy, patients lie on their left side on an examination table. Anesthesia is given. The doctor and medical staff monitor vital signs and attempt to make patients as comfortable as possible.
The doctor inserts a long, flexible, lighted tube called a colonoscope, or scope, into the anus and slowly guides it through the rectum and into the colon. The scope inflates the large intestine with air to give the doctor a better view. A small camera mounted on the scope transmits a video image from inside the large intestine to a computer screen, allowing the doctor to carefully examine the intestinal lining.
Once the scope has reached the opening to the small intestine, it is slowly withdrawn and the lining of the large intestine is carefully examined again. Bleeding and puncture of the large intestine are possible but uncommon complications of colonoscopy.
Removal of Polyps and Biopsy
A doctor can remove growths, called polyps, during colonoscopy and later test them in a laboratory for signs of cancer. Polyps are common in adults and are usually harmless. However, most colorectal cancer begins as a polyp, so removing polyps early is an effective way to prevent cancer.
The doctor can also take samples from abnormal-looking tissues during colonoscopy. The procedure, called a biopsy, allows the doctor to later look at the tissue with a microscope for signs of disease.
The doctor removes polyps and takes biopsy tissue using tiny tools passed through the scope. Tissue removal and the treatments to stop bleeding are painless.
Colonoscopy usually takes 30 to 60 minutes. Cramping or bloating may occur during the first hour after the procedure. The sedative takes time to completely wear off. Discharge instructions should be carefully read and followed.
Patients who develop any of these rare side effects should contact their doctor immediately:
- severe abdominal pain
- bloody bowel movements
At what age should routine colonoscopy begin?
Routine colonoscopy to look for early signs of cancer should begin at age 50 for most people—earlier if there is a family history of colorectal cancer, a personal history of inflammatory bowel disease, or other risk factors. For African American patients, screening colonoscopy should begin at age 45. The doctor can advise patients about how often to get a colonoscopy.