When you turn 50 years old, you enter the "procedure years". Fifty is the magic age for getting a screening colonoscopy. Why age 50? Most gastrointestinal cancers are more prevalent as a person ages. So guidelines are set to benefit the largest numbers of patients by recommending "screening" tests to detect cancer while it can still be removed completely and cured. The key word here is screening. That means there are no symptoms and the doctor is just doing surveillance. If a person has symptoms, family genetic cancers or other conditions that increase the chance of cancer the magic age of 50 doesn't apply and colonoscopy can be done at any time to diagnose a problem.
what your colon looks like with a good prep
There are also clinical guidelines for continuing follow-up screening and here is where it gets muddled. Gastroenterologists often don't adhere to these guidelines and patients can be confused as to when they should get a repeat exam. These guidelines assume the baseline colonoscopy was complete and the physician was able to get the scope up to the cecum, the bowel prep was adequate for good visualization and any polyps were removed. If you have a colonoscopy and a polyp was removed, remember to ask for the path report and keep it. This report shows what type of polyp it was because that makes a difference to when the next colonoscopy is due.
Here are the guidelines as recommended by the US Multi-Society Task Force on Colorectal Cancer:
No polyps - repeat in 10 years
Small (< 10mm) hyperplastic polyp in rectum or sigmoid - repeat in 10 years
1-2 Small (< 10mm) tubular adenomas - repeat in 5-10 years
3-10 tubular adenomas - repeat in 3 years
> 10 adenomas - repeat in less than 3 years
Any adenoma > 10mm - repeat in 3 years
Any adenoma with villous elements (villous or tubulovillous) or with high-grade dysplasia - repeat in 3 years.
Any sessile or serrated adenoma - repeat in 3 years
Serrated polyposis syndrome - repeat in 1 year
When can you safely stop screening? If the patient's life expectancy is less than 10 years, there is no reason to continue with screening colonoscopy.
In medicine, it is just as important to prevent overuse as it is to make sure everyone gets the right screening at the right time. If you are lucky enough to have a good primary care physician, she will make sure you are tested at the right time. But more and more people are trying to manage their own health without expert help and knowing your pathology report and following these guidelines will help you with timing.