Colonoscopy is an endoscopic procedure used to view large intestine (colon and rectum) using an instrument called colonoscope (a flexible tube with a small camera and lens attached at one end). The procedure can detect inflamed tissue, ulcers, and abnormal growths. It is used to diagnose early signs of colorectal cancer, bowel disorders, abdominal pain, muscle spasms, inflamed tissue, ulcers, anal bleeding, and non-dietary weight loss.
Colonoscopy is performed under general anaesthesia. The colonoscope is inserted into the rectum which gently moves up through the colon until it reaches the caecum (junction of small and large intestine). Colonoscopy provides an instant diagnosis of many conditions of the colon and is more sensitive than X-ray.
The colonoscope is then withdrawn very slowly as the camera shows pictures of the colon and rectum on a large screen. Polyps or growths can also be removed by colonoscopy which can be sent later for detection of cancer.