A rectal test is a medical research method that is carried out to detect or exclude diseases such as cancer, inflammatory bowel processes in a patient through an internal examination of the rectum. The method is based on the introduction of a special tube into the rectum to visually examine the condition of the mucous membrane, and if necessary, tissue samples are taken. Thus, rectal tests are painless and safe if the conditions of the procedure are observed, as a result of which accurate and effective diagnosis of the disease becomes possible.