43, canadian, suffer with chronic constiption, horrible bloating, abdominal pain. grandad had colon cancer and my doc won't send me for colonoscopy?

colonoscopy: The age at which people begin screening for colon cancer via a colonoscopy is 50. However, in patients with a strong family history of colon cancer, certain patients with polyps, GI bleeding or significant symptoms a colonoscopy may be performed at any age. See a GI specialist if your questions are not being answered.

colonoscopy is neces: Your grand dad is second degree family history. You should get colonoscopy.

IBS?: Chronic constipation and cancer do not generally go together. Sudden constipation and obstruction are associated with colon cancer. Risk of colon cancer is not generally increased with a granddad unless cancer occurred at very early age. Would have to assume you have already been evaluated for other causes of constipation. If all negative consider constipation predominant ibs.