Dartmouth-Hitchcock logo
Summer Flowers In This Section


What is a colonoscopy?
Why would a doctor recommend a colonoscopy?
What does a colonoscopy involve?
How long is the recovery after a colonoscopy?

What is a colonoscopy?

The large intestine (also called the large bowel), consists of the colon and rectum, which is the final part of your digestive system. In a colonoscopy, a doctor uses a thin, flexible tube to examine the entire large intestine. As the tube is advanced through the intestine, a video sensor in the tube transmits images to a television monitor.

Why would a doctor recommend a colonoscopy?

Some common reasons why a doctor may recommend a colonoscopy:

  • To check for polyps, or small growths that may lead to colon cancer. If polyps are found, the doctor can remove them painlessly. This is called a polypectomy.
  • To diagnose inflammatory bowel diseases like Crohn's disease and ulcerative colitis
  • To investigate frequent diarrhea, rectal or intestinal bleeding, a change in bowel habits, or weight loss
  • To take a biopsy of a growth in the large intestine

Photo: colonoscopyImages from inside the large intestine during a colonoscopy. The colon is a long tube, or tunnel. In the bottom photo, the doctor is using a tiny tool to remove a polyp.

What does a colonoscopy involve?

You will be given medication to make you relaxed and drowsy (some patients even fall asleep during the procedure). Because air is used to open the colon and create better images, you may feel some minor cramping.

Your doctor will slowly guide the colonoscope through the entire length of the large intestine, which will take about a half-hour. He or she will view the inside of your large intestine on the television monitor, and use a tiny forceps to take a biopsy, or tissue sample, of anything that looks out of the ordinary. This process is painless.

Because there is no way to tell if a polyp will or won't develop into cancer, a doctor removes any polyps he or she finds during a colonoscopy. This removal is called a polypectomy, and causes no pain. The doctor can remove small early cancerous (malignant) growths in the same manner.

Plan to be at the hospital for about three hours. More information about colorectal cancer screening.

How long is the recovery after a colonoscopy?

You will need some time in the recovery room for the effects of the medication to wear off. You will not be alert enough to drive on your own, so make sure a family member or friend can take you home. Plan on resting for the remainder of the day, and eat lightly at first. Minor symptoms such as gas or bloating will disappear within 24 hours.

Contact Us