Colonoscopy: Overview

A colonoscopy is the visual exam of the rectum and colon (large intestine). The exam is done with a tool called a colonoscope. The colonoscope is a flexible tube with a tiny camera on the end. This instrument allows the doctor to view the inside of your rectum and colon.

Colonoscopy

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Reasons for Procedure

It is used to examine, diagnose, and treat problems in your large intestine. The procedure is most often done for the following reasons:

• To determine the cause of abdominal pain, rectal bleeding, or a change in bowel habits
• To detect and treat colon cancer or colon polyps
• To obtain tissue samples for testing
• To stop intestinal bleeding
• Monitor response to treatment if you have inflammatory bowel disease

Possible Complications

Complications are rare, but no procedure is completely free of risk. If you are planning to have a colonoscopy, your doctor will review a list of possible complications, which may include:

• Bleeding
• Perforation or puncture of the bowel

Factors that may increase the risk of complications include:

• Smoking
• Pre-existing heart or kidney condition
• Treatment with certain medicines, including aspirin and other drugs with anticoagulant or blood-thinning properties
• Prior abdominal surgery or radiation treatments
• Active colitis, diverticulitis, or other acute bowel disease
• Previous treatment with radiation therapy

Be sure to discuss these risks with your doctor before the procedure.

What to Expect

Prior to Procedure

Your doctor will likely do the following:

• Physical exam
• Health history
• Review of medicines
• Test your stool for hidden blood (called "occult blood")

Your colon must be completely clean before the procedure. Any stool left in the intestine will block the view. This preparation may start several days before the procedure. Follow your doctor's instructions, which may include any of the following cleansing methods:

• Enemas —fluid introduced into the rectum to stimulate a bowel movement
• Laxatives—medicines that cause you to have soft bowel movements
• A clear-liquid diet
• Oral cathartic medicines—a large container of fluid to drink that stimulates a bowel movement

Leading up to your procedure:

• Talk to your doctor about your medicines. You may be asked to stop taking some medicines up to one week before the procedure, like:
  • Anti-inflammatory drugs (eg, aspirin)
  • Blood thinners like clopidogrel (Plavix) or warfarin (Coumadin)
  • Iron supplements or vitamins containing iron
• The night before, eat a light meal. Do not eat or drink anything after midnight.
• Wear comfortable clothing.
• If you have diabetes, ask your doctor if you need to adjust your insulin dose.
• Arrange for a ride home after the procedure.

Anesthesia

Your doctor may sedate you to decrease discomfort.

Description of the Procedure

You will lie on your left side with knees bent and drawn up toward your chest. The colonoscope will be slowly inserted through the rectum and into the bowel. The colonoscope will inject air into the colon. A small attached video camera will allow the doctor to view the colon's lining on a screen. The doctor will continue guiding the tool through the bowel and assess the lining.

A tissue sample or polyps may be removed during the procedure.

How Long Will It Take?

Less than one hour

Will It Hurt?

Most people report some discomfort when the instrument is inserted. You may feel cramping, muscle spasms, or lower abdominal pain during the procedure. You may also feel the urge to move your bowels. Tell the doctor if you feel any severe pain.

After the procedure, gas pains and cramping are common. These pains should go away with the passing of gas.

Post-procedure Care

If any tissue was removed:

• It will be sent to a lab to be examined. It may take 1-2 weeks for results. The doctor will usually give an initial report after the scope is removed. Other tests may be recommended.
• A small amount of bleeding may occur during the first few days after the procedure.

When you return home after the procedure, be sure to follow your doctor's instructions, which may include:

• Resume medicines as instructed by your doctor.
• Resume normal diet, unless directed otherwise by your doctor.
• The sedative will make you drowsy. Avoid driving, operating machinery, or making important decisions for the rest of the day.
• Rest for the remainder of the day.

Call Your Doctor

After arriving home, contact your doctor if any of the following occurs:

• Bleeding from your rectum—Notify your doctor if you pass a teaspoonful of blood or more.
• Black, tarry stools
• Severe abdominal pain
• Hard, swollen abdomen
• Signs of infection, including fever or chills
• Inability to pass gas or stool
• Coughing, shortness of breath, chest pain, severe nausea or vomiting

In case of an emergency, call for medical help right away.