what are the risks of a colonoscopy

A colonoscopy poses few risks. Rarely, complications of a colonoscopy may include:

Adverse reaction to the sedative used during the exam
Bleeding from the site where a tissue sample (biopsy) was taken or a polyp or other abnormal tissue was removed

A tear in the colon or rectum wall (perforation)

After discussing the risks of colonoscopy with you, your doctor will ask you to sign a consent form authorizing the procedure.