Colonoscopy

A colonoscopy is a test performed to detect changes or abnormalities in the rectum (where the stools are stored before being eliminated) and colon (large intestine).

A colonoscope is a flexible, thin tube with a camera on one end, that helps in the transmission of the images of the inside of the colon to a video screen.

A colonoscopy may be performed by a gastroenterologist, colon and rectal surgeon, or general surgeon.

The different types of colonoscopy procedures are:
1. Colonoscopy: The procedure involves the insertion of a colonoscope through the anus (from where stools are removed) into the large intestine. The colonoscope has a camera on one end that helps in transmitting the images of the inside of the colon to a video screen.
2. Virtual colonoscopy: This is a type of computerized tomography (CT) scan that uses x-rays to create images of the inside of the large intestine. This procedure does not involve colonoscope insertion into the large intestine.

A colonoscopy may be recommended by the doctor to diagnose and treat diseases and conditions of the colon and rectum that include:

• To find the underlying cause of abdominal (stomach) pain
• To find the cause of bleeding symptoms like rectal bleeding, blood in stools, black and tarry feces
• To find potential bleeding sites in case of a person having anemia (low red blood cell count)
• To diagnose the cause of chronic (long term) diarrhea or constipation
• To detect and remove colon polyps (abnormal growths in the large intestine), reducing the chances of developing colon cancer
• To diagnose the underlying cause of unexplained loss of weight
• For screening of colon cancer in case of people who are 50 years or older

The following symptoms seen in a person may indicate the need for a colonoscopy:

• Abdominal pain
• Rectal bleeding
• Chronic diarrhea
• Chronic constipation
• Black, tarry stools
• Blood in stools
• Unexplained loss of weight

It is essential to cleanse the bowel for a successful colonoscopy. This is done in the following ways:

• Changes in diet: The doctor recommends certain dietary changes the day before the procedure, like eating a light breakfast and lunch and skipping dinner, or taking a liquid-only diet.
• Consumption of only clear liquids: The doctor may tell the patient to drink only clear liquids, like water, broth, tea or coffee without milk the day before the procedure.
• Enemas: An enema kit may be used by the patient the night before the procedure or a couple of hours before the procedure.
• Laxatives: The doctor may recommend certain laxatives to be taken a day before the procedure, either in pill or liquid form. Sometimes, it may be recommended to take them on the morning of the procedure.

Tell the doctor about any medications that the patient may be taking, especially if the patient is suffering from high blood pressure, diabetes, or heart problems.
Tell the doctor if the patient is taking any supplements or medications containing iron.
The doctor may recommend stopping taking blood-thinning medications like warfarin and aspirin a few days before the procedure. 
The doctor may recommend an adjustment in the dosages or stopping of certain medications that the patient may be taking.

The colonoscopy procedure is generally performed under a light sedative, which makes the patient feel drowsy and relaxed during the procedure. In certain cases, deeper sedation or anesthesia is used. The patient is also given a pain-relieving medication to ease any pain or discomfort during the procedure.
The procedure is performed as follows:

• The patient lies on the left side and the knees are pulled up to the chest during the procedure.
• The doctor gently inserts the colonoscope through the anus into the rectum and colon.
• The image obtained is transmitted onto a video screen.
• The doctor then inserts air or carbon dioxide into the colon to inflate it and give a better view of the intestinal lining.
• The stools and fluids are removed through the colonoscope as required.
• The doctor then slowly and gently pulls out the colonoscope from the colon and rectum and examines it for any abnormalities.
• The doctor may perform other procedures like tissue biopsy (the removal of a sample of abnormal tissue growth and sending it to the laboratory for evaluation) during colonoscopy.
• The procedure takes approximately half an hour to one hour to complete.

The following are the post-procedure steps following a colonoscopy:

• Colonoscopy is usually performed as an outpatient procedure, that is, the patient goes home on the same day of the procedure.
• It takes about an hour before the patient starts recovering from the effect of the sedative following a colonoscopy.
• It takes up to a day to recover fully from the effect of the sedative.
• Avoid driving or going to work for the day following a colonoscopy.
• If a polyp is removed during colonoscopy, the patient is advised to eat a special diet temporarily.
• It is normal for the patient to pass gas or feel bloated for a couple of hours after the procedure, as the air from the colon is cleared.
• Walking is recommended to relieve the discomfort of the patient.
• It is normal to notice a small quantity of blood in the first bowel movement after a colonoscopy examination.
• The patient should immediately consult the doctor if he/she continues to pass blood, has abdominal pain, or fever.

The side effects of colonoscopy may include the following:

• Allergic reaction to the medications or sedative used
• Infection
• Bleeding
• Dehydration
• Nausea
• Vomiting
• Rectal discomfort
• Puncture of the large intestine

The doctor reviews the results of the colonoscopy and shares the result with the patient.

1. Negative result:

• The result of a colonoscopy is considered to be negative if no abnormalities are found by the doctor in the colon.
• Another colonoscopy is recommended by the doctor after 10 years if you have no other risk factor for colon cancer except an increased age.
• Another colonoscopy is recommended by the doctor after 5 years if you have a history of polyps in the previous colonoscopy procedures.
• Another colonoscopy is recommended by the doctor after 1 year if a residual stool was present in the colon, which had prevented the complete examination of the colon.

2. Positive result:

• The results of colonoscopy are considered to be positive if any polyps or abnormal tissue is found by the doctor in the colon.
• If polyps are found, the doctor removes them during colonoscopy (biopsy) and sends them to the laboratory to check if the polyps are precancerous, cancerous, or non-cancerous.
• Depending on the number and size of polyps, one may need regular follow-ups to check for future polyps.
• If the doctor finds one or two polyps that are less than 1 centimeter in diameter, a repeat colonoscopy may be recommended in 5 to 10 years, depending on other risk factors for colon cancer.
• If the polyp or any other abnormal tissue cannot be removed during a colonoscopy, the doctor may recommend a repeat exam with a gastroenterologist to remove the large polyps.

A colonoscopy may be recommended sooner in the following cases:

• If there are more than two polyps
• If the polyps are cancerous
• A large polyp larger than 1 centimeter in size
• Polyps and residual stool in the colon, which prevents the complete examination of the colon
• Polyps have certain cell characteristics that are indicative of a higher risk of developing future cancer

The cost of colonoscopy varies depending on why it is being performed, and the condition of the patient.
The cost also varies amongst different doctors in different hospitals. Normally, the cost of a colonoscopy procedure in India is anywhere between INR 1,000 to INR 25,000.