A dynamic stochastic model for colon and rectum cancer is developed to obtain the optimal ages to perform colonoscopies. The currently recommended guideline for colonoscopy is to test at ages 50, 60, 70, 80 and 90. Our Monte Carlo simulation yields a cost/life-year saved of $54,919.62 for the official policy. We ask the following: if we could reallocate the 5 tests between the ages of 50 and 90, which ages for testing would give the lowest cost/life-year saved? Of the 91,309 possible policies 43,026, or 47%, have a better cost per life-year saved than the currently recommended guidelines. The policy with the lowest cost is to test at the ages of 64, 71, 73, 79, 85 with a cost of $38,081.37 per life-year saved. An improvement of 30% in the cost/life-year saved. The framework developed in this paper can be further used to evaluate the cost effectiveness of current guidelines for other cancers. The policies can be personalized by sex and race to have better cost- effectiveness ratios. Finally, guidelines can be developed to equate cost per life-year saved across different cancers.