Gastroenterology

Colonoscopy is a visual exam of the lining of the large intestine, also called the large bowel or colon, with a colonoscope. A colonoscope is a flexible tube as thick as your finger that looks like a black hose. At the tip of the colonoscope, there is a light and a tiny video camera that allows the doctor to view the inside of the colon on a TV monitor.

Reasons for Colonoscopy

• To identify and remove pre-cancerous growths (polyps) before they become cancer
• To diagnose colorectal cancers
• To identify and stop the source of lower intestinal bleeding
• To investigate causes for changes in bowel habits
• To investigate causes of lower abdominal pain

One Week Before Colonoscopy

• Do not take iron for one week before the procedure, unless told otherwise by your doctor.
• Do not take aspirin or other anti-inflammatory or blood-thinning drugs for one week before the procedure, unless told otherwise by your doctor.
• If you require antibiotics before seeing the dentist, tell your doctor because you may need antibiotics before the colonoscopy as well.
• Arrange a ride to and from the procedure.
• Pick up cleansing preparation chosen by your doctor from drug store.

One Day Before Colonoscopy

• Your colon must be completely cleaned out before the procedure. Any stool left in the colon will block the doctor’s view and decrease the success of the procedure. It is in your best interest to have a clean colon the day of the exam. This will make the colonoscopy safer, easier, and more accurate. Otherwise, you may need to repeat the colonoscopy at another time with a better preparation.
• You will receive detailed instructions on the preparation. A number of cleansing methods may be used, including laxatives and a clear liquid diet. You may be asked to drink a liquid solution that aids in cleaning the colon.
• After breakfast the day before the colonoscopy, you will be on a clear liquid diet the rest of the day.
• Do not eat or drink anything for 8 to 10 hours before the procedure.
• If you have insulin-dependent diabetes, ask your doctor about any adjustments to your insulin dose.

The Procedure

• Arrive in the endoscopy unit one hour before the procedure.
• A nurse will take a history and insert a needle into a vein to establish intravenous access.
• Medication is given intravenously to sedate you and to decrease discomfort. The goal is to keep you comfortable during the procedure. This is not general anesthesia. Colonoscopy is very well tolerated and rarely causes much pain. You may feel pressure and cramping during the procedure, but the majority of patients do not remember the procedure due to the sedative medications.
• You lie on your left side with knees bent. The endoscopist will perform a rectal exam with a finger and then will slowly insert the lubricated colonoscope through the rectum and move the colonoscope gently around the bends of the colon. The doctor will assess the lining of the colon looking for any abnormalities.
• If anything abnormal is seen like a growth or a polyp, this may be removed for analysis.
• The colonoscopy usually takes about 30 minutes. Expect to stay at the endoscopy center for another hour or two until the sedative wears off.

Possible Complications

• Serious complications are very uncommon. One possible complication is a perforation or tear through the bowel wall that rarely may require surgery. Bleeding can occur at the site of biopsy or polyp removal, but is usually minor and self-limited.

After the Colonoscopy

• You may feel bloating, gas, or cramping for 24 hours.
• Do not drive, operate heavy machinery, or make major decisions for the rest of the day.
• Rest for the remainder of the day.
• Resume medications as instructed by your doctor.
• Resume your regular diet, unless told otherwise by your doctor.

Follow-up

• Your doctor will usually give you a preliminary report after the medication wears off and you are more alert. The results from a biopsy will take one to two weeks to be completed so call your doctor for the results.

Call Your Doctor If Any of the Following Occurs:

• Signs of infection, including fever and chills
• Bleeding
• Black, tarry stools
• Severe abdominal pain
• Coughing, shortness of breath, chest pain, severe nausea and vomiting

Resources

• National Digestive Diseases Information Clearinghouse, NIH
  http://digestive.niddk.nih.gov/
• American Society for Gastrointestinal Endoscopy
  http://www.askasge.org/

Sources

• American Gastroenterological Association
• National Digestive Diseases Information Clearinghouse