Compliance with fecal occult blood testing: the role of restrictive diets.

In this clinical trial, 786 patients screened for colorectal cancer with fecal occult blood testing were assigned to either a "diet" or "no diet" group to examine the effect of advice to restrict intake of red meat and peroxidase-containing vegetables on patient compliance and positivity rates. Restrictive diets did not significantly decrease compliance. Interviews of patients in the "diet" group demonstrated that the majority followed instructions. Positivity rates were similar in the two groups, and clinically significant lesions were found with comparable frequency.