Cleaning and disinfection are two necessary and equally important steps to prevent transmission of infection from patient to patient by the endoscope and accessories. There is no evidence that complete sterility is necessary; high-level disinfection is recommended. Controversy remains as to how "high level" this disinfection must be. It is important that these processes not become complicated, difficult, or intimidating. They must be efficacious and yet safe for the scope as well as for the attending staff. It is strongly recommended that the clinician fully understands the cleaning and disinfection steps and not inhibit his or her staff's ability to perform them correctly. It is important that we use these relatively new and important diagnostic equipment tools to improve the health of the public. There are several studies now that suggest that screening flexible sigmoidoscopies may be of value in decreasing mortality from colonic adenocarcinomas. It is important that we remain focused on our overall mission while at the same time "do no harm."