How often should you have a colonoscopy?

Depends: If you are over 50 and have no prior hx or family history of colon polyps or cancer or inflammatory bowel disease, the current recommendations are once every 10 years. If any of the above are positive it should be more often, at least every 5 years and maybe more often depending on your specific risk factors. Abdominal pain, in of itself, is not an indication for colonoscopy in my opinion.

It depends on indica: If it is for screening for colon cancer, then once every 10 years is considered adequate but it can be done more often if there is an abnormality that requires close monitoring.