What is a colonoscopy?
Colonoscopy is a procedure that uses a long, flexible, narrow tube with a light and a tiny camera at one end, called a colonoscope or telescope, to view the inside of the rectum and the entire colon. Colonoscopy can show swollen and irritated tissue, ulcers, and polyps (extra pieces of tissue that grow on the intestine lining). A gastroenterologist (a doctor specializing in digestive diseases) performs this procedure.
This procedure is different from virtual colonoscopy, which uses a combination of x-rays and computer technology to create images of the rectum and the entire colon.
What are the rectum and colon?
The rectum and colon are part of the gastrointestinal tract, a series of hollow organs joined in a long, twisting tube from the mouth to the anus (a 1-inch-long opening through which stool passes out of the body). The body digests food using the movement of muscles in the gastrointestinal tract, along with the release of hormones and enzymes. The organs that make up the gastrointestinal tract are the mouth, esophagus, stomach, small intestine, large intestine (which includes the appendix, cecum, colon, and rectum), and the anus. The intestines are sometimes known as the entrails. The last portion of the digestive tube, called the lower gastrointestinal tract, consists of the large intestine and the anus.
Why is a colonoscopy performed?
A colonoscopy is done to help diagnose
- changes in bowel habits
- abdominal pain
- anal bleeding
A gastroenterologist also performs a colonoscopy as a screening test for colon cancer. Screening tests to check for diseases when a person has no symptoms. Screening can find illness at an early stage when a health care provider is most likely to cure the disease.
Get screened for colon cancer.
The American College of Gastroenterology recommends colon cancer screening if:
- at age 50 for people without increased risk of having the disease
- at age 45 for African Americans, because they are at higher risk of developing the disease 1
A gastroenterologist may recommend earlier screening for people with a family history of colon cancer, a personal account of inflammatory bowel disease (a long-lasting disorder that causes irritation and sores in the gastrointestinal tract), or other risk factors for colon cancer.
Medicare and private insurance companies sometimes change coverage for cancer screening tests. People should check with their insurance company to find out how often they can have the screening colonoscopy covered by their insurance.
How does a person prepare for a colonoscopy?
Preparation for a colonoscopy includes the following steps:
- Talk to a gastroenterologist. When people schedule a colonoscopy, they should talk to their gastroenterologist about their medical conditions and all prescription and over-the-counter medications, vitamins, and supplements they take, including:
- aspirin or medicines containing aspirin
- nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen
- arthritis medications
- diabetes medications
- iron-containing vitamins or iron supplements
What can a person expect after a colonoscopy?
After the colonoscopy, the person can expect the following:
- People may need to stay in the hospital or outpatient center for 1 to 2 hours after the procedure.
- During the first hour after this test, cramping or bloating may occur.
- It takes a while for the anesthesia to wear off completely.
- Full recovery is expected the next day, and people can return to their regular diet.
- A health care team member will review the discharge instructions with the person or accompanying friend or family member if the person continues to be dizzy and provide a written copy. The person must follow all the instructions given to him.
- A friend or family member will need to drive the person home after the procedure.
- If the gastroenterologist removed the polyps or performed a biopsy, it is customary to see slight anal bleeding.
What are the risks of colonoscopy?
Colonoscopy risks include the following:
- Perforation (hole or tear in the lining of the colon)
- Diverticulitis—a condition that occurs when small pouches in the colon, called diverticula, become infected, inflamed, and irritated.
- Cardiovascular events, such as heart attack and low blood pressure; or irregular, fast, or slow heartbeat
- Sharp abdominal pain.
- Death, although this risk is rare.