The stomach must be completely empty. You should not eat or drink anything, including water, for approximately 6 hours before the examination. Your doctor will be more specific about the time to begin fasting, depending on the time of day that your test is arranged.

Colonoscopy is used to see your large intestine from the rectum to the caecum. It is useful for diagnosing polyps, cancer of the large intestine, ulcerative colitis and other disorders of the large intestine.