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You’ve been told you need a colonoscopy, now what?

Colonoscopy is a valuable exam for the diagnosis and treatment of many diseases of the large intestine, and for colon cancer screening.

To have a successful colonoscopy, your bowel must be empty for your doctor to clearly view the colon. To do this, it is very important to read and follow all of the instructions. You will be informed of the type of prep you will need to drink the day of or before your procedure. You will also be informed of where your procedure will take place.

Review these documents to help you prepare for your procedure:

Colon prep instructions

Click the respective link to access the instructions for the prep you must follow:

What to expect during the procedure

During a colonoscopy, the gastroenterologist inserts a colonoscope, a long flexible tube that is about the thickness of a finger, through the rectum to examine the lining of the colon. If the doctor sees a suspicious area, a polyp or needs to evaluate an area of inflammation in greater detail, he or she can pass an instrument through the colonoscope to remove the polyp or tissue (biopsy) for examination in the laboratory. Biopsies are taken for many reasons and do not necessarily mean that cancer is suspected.

The day of:

  • A nurse will take your medical history.
  • An IV will be started. You will be given medication through an IV to make you relaxed and sleepy.
  • While you are lying on your left side, the colonoscope is inserted into the rectum and gradually advanced through the colon while the lining is examined thoroughly.
  • The colonoscope is then slowly withdrawn while the intestine again is carefully examined.
  • The procedure usually is well tolerated. There may be some discomfort during colonoscopy, but it usually is mild.
  • The procedure will take approximately 30 to 45 minutes.
  • In rare cases, passage of the colonoscope through the entire colon cannot be achieved. A limited examination may be sufficient if the area of suspected abnormality was well visualized.

What happens after the colonoscopy?

  • You will be kept in the exam area until most of the effects of the medication have worn off, which takes about an hour.
  • You may feel bloated after the procedure because of the air that was introduced while examining the colon.
  • You will be able to resume your diet unless you are instructed otherwise.
  • Avoid alcohol, driving and operating machinery for 24 hours following the procedure.
  • If polyps were removed or a biopsy was taken, the doctor performing your colonoscopy will tell you when it is safe to resume taking your blood thinners.
  • If a biopsy was taken or a polyp was removed, you may notice light rectal bleeding for one to two days after the procedure. If you have a large amount of rectal bleeding, high or persistent fevers, or severe abdominal pain within the next 2 weeks, go to your local emergency room and call the doctor who performed your exam.
  • You will be given an instruction sheet before you leave the hospital.

Complications from the procedure

Colonoscopy is safe and associated with very low risk when performed by doctors who have been specially trained and are experienced in these procedures. Complications can occur, but are rare. One possible complication is perforation, in which a tear through the wall of the bowel may allow leakage of intestinal fluids. This complication usually requires surgery, but may be managed with antibiotics and intravenous fluids in selected cases. Bleeding may occur from the site of biopsy or polyp removal. It is usually minor and stops on its own, or can be controlled by cauterization (application of electrical current) through the colonoscope. Rarely, transfusions or surgery may be required. Localized irritation of the vein may occur at the site of medication injection. Other risks include drug reactions and complications from unrelated diseases such as heart attack or stroke.