Your doctor might recommend a colonoscopy examination if you present symptoms that suggest abnormalities in your colon or rectum. These symptoms include rectal bleeding, changes in bowel habits (constipation or diarrhoea), blood in the stool, abnormal weight loss and abdominal pain. Colonoscopy can also be used as a routine screening for people who have a history of colon cancer or polyps (non-cancerous growths in the lining of the colon) and to check for inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis (sores in the large intestine). In addition, colonoscopy can be used to take a biopsy (microscopic examination of tissue taken from the colon) to identify an infection and can be used to remove colon polyps.