Plenty of doctors promote bad information online. Certainty does not equal expertise. I learned long ago that it's better to provide good information that try to battle bad information, so I humbly offer this level 1 evidence on the safety and efficacy of colonoscopy: 1. Colonoscopy is safe, and the risk of perforation during screening is 3.1 per 10,000, or 0.031%. If you are that unlucky 1 in 3,226 people, the risk of it killing you is less than 5% Source: jamanetwork.com/journals/jam… 2. Colonoscopy reduces your chance of getting colorectal cancer, and it reduces your chance of dying from colorectal cancer. In fact, there's a 68% reduction in CRC mortality with colonoscopy. Source: acpjournals.org/doi/10.7326/… I try my best to ignore physicians who use twitter to promote pseudoscience and generate traffic to their websites, but it's Colorectal Cancer Awareness Month, so I feel obligated to share my thoughts.