“What is the follow-up protocol after colonoscopy if polyps are detected?”

The follow up depends on the number, size and type of polyps that were found.
For example, if 1-2 small tubular adenomas are removed, then a colonoscopy is usually recommended in 7 years per the current published guidelines.

Normally, at least one of the polyps are removed and sent to the pathology lab where they are diagnosed either benign og malign. You will be informed in any case, but if not, contact your GP and get the low down. If he for some odd reason doen't have the communication. contact the surgeon's office and get the low down. If for some odd reason they did not send the sample to the pathology lab, ask for a retake without charge, or threaten to sue for malpractice.