Colonoscopy Procedure

Colonoscopy Procedure

What is a Colonoscopy?

Your doctor has recommended that you have a colonoscopy. A colonoscopy is a test that allows your doctor to examine the lining of your colon for any abnormalities. The colonoscopy, which is a thin, flexible, fiber optic instrument, is passed from your rectum to your cecum (the point where the small intestine joins with the large intestine). Colonoscopy is considered the “gold standard” to evaluate intestinal inflammation, ulceration, bleeding, diverticulosis and tumors. It is possible to remove most colon polyps during a colonoscopy, there is no pain or any sensation as the polyp is removed.

A colonoscopy is a safe and highly effective procedure. The procedure is quick (usually between 10 – 40 minutes) and generally quite painless. You may be given sedation if required to make you relaxed and sleepy. Usually, patients remember very little and are pleasantly surprised by how easy the procedure was.


Do I have any alternatives for the test?

Depending on your symptoms and circumstances, it may be possible to diagnose your bowel condition using a different test. Alternatives available are a Barium enema, CT scan, or, recently, virtual colonoscopy or a CT colonography. None of these tests see the textural details of the mucosal lining under magnification as does a colonoscopy. In your specific instance, you may talk to your doctor about the relevance of these tests over a colonoscopy.


Are there any risks in the procedure?

Following colonoscopy, you may feel a little bloated for a short while. The common side effects of the sedatives used include drowsiness, light-headedness and nausea. But the risk of a complication happening during a diagnostic test is negligible(less than 0.01%). You will realize that you yourself can minimize the risks when you read the following.

Being on blood thinning medications (Warfarin, Clopidrogel, Ticlodipine, Aspirin, Naproxen) may increase the risk of bleeding even from a simple biopsy during the colonoscopy. You may discuss this with the endoscopist or your treating doctor. It is fine to continue taking Acetaminophen or Paracetamol.

You need to inform the endoscopy team in case you are already receiving the following medication, as adequate precautions can be taken during the procedure:

Diabetes medications such as Insulin or oral diabetes medications

Heart problems or related surgeries, Heart valve replacement & Joint replacement; Chemotherapy treatments or immunosuppressive drugs (steroids, Azathioprine, etc) (you may then need to have a prophylactic antibiotic during colonoscopy )

Kidney problems (to prevent drug side effects)

Some medications such as for seizure disorders should not be stopped.


Are the Endoscopes and instruments clean?

Most major Hospitals have stringent protocols for sterilization, and we assure that all aseptic Precautions are in place to prevent transmission of infections during Endoscopy.

What actually happens in Colonoscopy


With you resting on your left side, your doctor will gently examine your back passage with a gloved finger & lubricating jelly before carefully inserting the colonoscope.

 Air is then usually passed through the tube into the colon to make it expand and the bowel wall easier to see. This may briefly cause pains similar to having wind and you may get an urge to go to the toilet, but as the colon is empty, this won’t be possible.

 Most people pass some wind. There is no need to feel embarrassed about this as your doctor will expect this to happen.


During the procedure, you may be asked to change your position – for example turning from your side onto your back. This helps your doctor to examine different areas of the colon more easily. If necessary, your doctor will take a biopsy and/or remove polyps. This is done using special instruments passed inside the colonoscope, and is quick and painless

Okay, so I wish to prepare myself for the test!


What diet do I need to take on the day before the test?

If you are severely constipated, there is an issue about diet the previous day. Else, just eat as normal. Restrictions on food are more in the west, as their diet is different. Indian colons are easier to prepare for the procedure, as we usually eat a lot of fiber in our life.

However, if you regularly use laxatives as a habit (like choorans, etc); please take them the night before as usual for you.  Patients with constipation but not using laxatives may be helped by taking 2 tablets of Dulcolax the night before.

For your doctor to see the bowel wall clearly, the bowel needs to be completely empty. To help clear it out you will be asked to follow one of two protocols if you want a faultless procedure.

  1. Not so constipated persons:

Such persons are suggested to drink two liters of a solution of polyethylene glycol (Peglec or Colopeg) that causes temporary diarrhea. It comes in 2 flavors, which, unfortunately, only partially mask a somewhat unpleasant taste. Refrigerating the solution may make it more palatable. Drinking such a large volume of cold solution may cause a patient to feel chilled, but the sensation is temporary. Do not add flavoring (additional sugar or salt) to the solution. Many patients say that drinking the purgative solution is the most unpleasant part of the examination! I usually prefer to ask patients to make the solution the night before; so they will not loose time making it when they wake up. You could drink it in two hours about 4 to 6 hours before the scheduled time for the test; at the rate of a glass (200 ml) every 10 minutes. In case you feel nauseous, slow down, so you do not throw up and need to start with a fresh two liter solution all over. You will pass about 5 to 8 watery stools, the last of which are expected to be the color of the solution you drank.


  1. The “really constipated” persons:

The second method involves drinking a solution called Exelyte (2 bottles of 45 ml each in a box) mixed in 300 ml lime juice or Limca over half an hour, followed by several glasses of fluids. This preparation is easier to consume (just 2 glasses of a juice, each over 15 minutes) than the Polyethylene glycol. However, Exelyte is a cathartic; it makes you loose body water to make loose stools and you should be careful not to get dehydrated. I prefer to check that you do not already have a borderline renal damage (do a Blood urea & creatinine test); else giving this solution and not hydrating later may aggravate the kidney damage. It also contains a large amount of phosphorus, which may be a problem for people with heart or kidney conditions.


  1. What should I do after consuming the preparation liquid?

It is very important that you drink liquids frequently throughout the day to avoid dehydration. Drink water, soft drinks, fresh as well as canned juices, chicken or vegetable soups, coffee or tea (no milk; sugar is fine). Avoid foods with seeds the previous day (brinjal, guava) as well as supari & saunf; it remains undigested and then clogs our scopes!


4. If you prefer having sedation for the colonoscopy,

Please stop consuming liquids at least 2 hours before the scheduled procedure.


What time, and from when do I have to start taking the laxatives?

From the time you start drinking the solution, in a normal person it takes about 4 hours for a non constipated patient to leave home for the test and travel. Patients coming from close by are thus advised to take the solution of Peglec powder in the morning from 6 am to 8 am at the rate of one glass every 10 minutes. They then can come for the test by 10 or 11 am.

Outstation patients may either need to start earlier; count about 4 hours back when you should be leaving your home for the test. That is the time to start consuming the preparation fluid.

A stronger laxative like Exelyte is associated with some cramping even after full cleansing. You may thus start taking the Exelyte even 5 hours before the procedure.

For tests done in the morning, my personal preference is NOT to give the preparation at night. It will keep you awake into the night, and sometimes there is residue in the colon if your test is closer to noon.


Will it pain? Will it be done under sedation or anesthesia?

In my hands I make sure there is no pain, thus I have completed over 95% of my colonoscopies even without putting a venous access. In case there has been surgery on your tummy, it is likely that the loops of intestine stick to the abdominal wall; in such patients we definitely arrange sedation. If you get pain during the test, the anesthesia team is just next door; so we can keep you comfortable and pain free. If you do need sedation, you may need to remain under observation for another hour after the procedure; and will not be able to drive home on your own.


I would still prefer sedation for the procedure!

Our Anesthesia team will make sure you are comfortable throughout the procedure. It would be preferable for them to review your records in advance, so they can plan appropriately for the day of the procedure. The sedative will be injected through the cannula placed in the back of your hand, and you should start to feel relaxed and drowsy almost immediately. Sedatives can sometimes affect your breathing, so the amount of oxygen in your blood will be monitored constantly through a clasp on your finger and you may be given extra oxygen through a mask.

After your procedure is complete you will be taken to the recovery area. The nurses there will continue to monitor your blood pressure, pulse and oxygen saturation. Your “significant other” or friend may come in & sit with you in recovery at this time. You may need to stay in the recovery area for even up to three hours.

Plan so you do not need to drive, operate machinery, sign any important documents or make important decisions until the next day. You should not exercise strenuously until the next day. You must make arrangements for a responsible adult to drive you home after your procedure. Taxis and buses are not permitted unless you are accompanied by a responsible adult.


What to Wear?

Please wear loose, comfortable clothing. Please leave your valuables at home. Wear comfortable, stable shoes since you may be a little unsteady when you leave. You will be changing into a patient gown before the procedure.


And how much time does the test usually take?

You will leave the hospital in 1/2 hour from your arrival if sedation is not given. The actual procedure is between 10-15 minutes.


The colonoscopy is for a child!

Children under a year may not take a laxative easily. They will need to stick to a “Low Residue” diet; thus will not be eating anything in their meals that will add bulk to the stools. In addition; they will need to take a regular laxative every night to remove the residue already there. Sometimes they may need to be on this diet for between 3 to 5 days before they are well prepared. Be in touch with your doctor through this preparation as individual variations may be needed. You would not want your baby to be given full anesthesia, and the procedure not happen due to poor preparation!

My experience is that children below teens will always need sedation. That procedure is the same and completely safe. Children are smaller adults; the test is sometimes done with a video gastroscope than a colonoscope; as the size is appropriately thinner as well as softer to handle.


What if polyps are seen during the colonoscopy?

Polyps are always removed if found. They are then examined microscopically the see if they could be markers of turning malignant. Thus in case polyps are seen during the test, they can be removed if:

You are unlikely to bleed when the polyp is cut (you are not on blood thinners, your clotting tests are normal, etc)

The Endoscopy Suite you test is being done in has the facilities for a polypectomy

You are prepared to stay for observation after the procedure if required (this could be sometimes overnight).

You are aware of the cost escalation when the procedure changes from a plain colonoscopy to a polypectomy (this can often be a three times escalation)




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