The risks of the colonoscopy procedure include a perforation in the rectum wall or colon, bleeding from the removal site of a polyp or tissue sample, as well as a negative reaction to the sedative used. The doctor goes over these risks before having the patient consent, notes Mayo Clinic.
Even with these risks in mind, colonoscopy is a procedure in which the benefits more than outweigh the risks. The colonoscopy screens patients for colon cancer, a disease in which early detection is crucial for survival. People who are 50 years of age are older should undergo colonoscopy to ensure that no cancerous growths are forming, according to Mayo Clinic.