Though doctors don't recommend periodic colonoscopy screenings for those without a history of colon cancer until age 50, there is no upper age limit to forgo the testing.

Several callers asked about being "too old" to be screened during Saturday's monthly Deseret News/Intermountain Healthcare Hotline. The free program is offered monthly as a public service and focuses on a different health topic each session.

Dr. Brent Christensen, a surgeon at LDS Hospital, said one 89-year-old caller who has a family history of polyps wanted to know if a colonoscopy was still necessary. "Those with a history, in particular, need to have one. There are some people who say if you are 80 or older, you don't need to be screened any more. I'm not one of those.

"The decision is determined more based on a person's own physiology and family history and what the potential risks are," he said, adding age is often less of a factor in the decision making than other considerations.

Other callers asked about constipation and dietary concerns. Though a diet high in fiber has not been shown to prevent colon cancer, a high-fiber diet does help ease problems with constipation that can be complicated with age, as nerves in the colon become less effective.

Other questions concerned the frequency for colonoscopy if polyps have been found. Christensen said in that case, the interval between screenings should be every three years, rather than ever five years.

The procedure can also be done while a patient is taking blood thinners, but if there is a polyp or other growth that should be removed, the procedure would have to be repeated at a later date to avoid potential bleeding problems, he said.

Dr. Kerry Fisher, chief of surgery at LDS Hospital, also answered callers' questions, including one about irritable bowel syndrome and whether it puts a patient at increased risk for colon cancer.

"After 10 years, it does significantly increase the risk of cancer, so it needs to be followed closely," he said.

Current research shows that genetic factors have the greatest correlation to colorectal cancer, and those who carry a specific hereditary mutation of the APC gene carry an almost 100 percent risk of developing colon cancer by age 40.

The two-hour call-in program received dozens of calls ranging from Logan to St. George and from all along the Wasatch Front.

e-mail: carrie@desnews.com