Colonoscopy refers to the procedure that help the doctor, usually a gastroenterologist, to detect abnormalities in the colon, rectum or the large intestine. The procedure is done with the help of a colonoscope, which is a 4 feet long, thin, flexible tube with a camera attached on the tip. The colonoscope is inserted through the anus and slowly advances into the rectum and colon and gives clear images of the inside of the digestive system. It is a very effective procedure to find ulcer, tumors, colon polyps, bleeding and inflammation in the colon. It is also used to remove abnormal tissues for a biopsy.

In order to perform colonoscopy successfully, the colon needs to be cleaned thoroughly (colon prep) and other preparations must be done. Cleaning of the colon will be achieved after drinking special cleansing solutions and liquid diet for a few days before the exam. You will be given detailed instructions on how to be prepared for the test. The doctor will inject general anesthesia to put you to sleep during the procedure. Once the effects of the anesthesia are on, the doctor will insert the colonoscope in your anus and move it forward gradually to the colon. The camera attached will provide inside images on the computer screen. The doctor may also inflate air into your colon to get a better view. If there is any cancerous growth in your colon, the doctor may use special tiny tools such as loops, forceps or swabs to cut the growth for a biopsy.

Once it is done, the scope is pulled out of the anus and the air will escape. The area will be cleaned with tissues and if you feel any cramps, the passing of air will help you feel relieved. The whole procedure usually takes 30-45 minutes, but it may take long depending on the findings during the test.


Complications are quite rare and minor with colonoscopy if it is performed by an experienced gastroenterologist. These complications could be:

  • Rectal bleeding

  • Perforation

  • Reaction to anesthesia

  • Irritation to the vein

  • Abdominal pain

  • Fever and chills

  • Firm or swollen belly

Notify your doctor at once if you feel any of these complications.

Post operative care

Once the test is complete, you can return home on the same day after a few tests. It takes about an hour or so to recover from the effects of anesthesia. Since colonoscopy is a procedure to detect abnormalities in the stomach, you will be called back in the hospital once the results of the test are out.

You may feel bloated for a few hours after the test. Walking will improve the bloating as it will release the air.

The doctor may recommend a special diet to you if a polyp is removed during the procedure.