How often do you need a colonoscopy if they find pre cancerous polyps?

It depends on: several things including the type, size, and number of polyps. Your polyps were likely adenomas, not hyperplastic polyps, if you were told they were pre-cancerous. If you only had 1 or 2 small (<10 mm) adenomas, next colonoscopy in 5-10 years. But >2 adenomas, or >10 mm in size, almost all guidelines suggest repeat colonoscopy in 3 years. Serrated polyposis syndrome is annual exam. Hope helpful