The invention relates to the technical field of medical instruments for the rectum, and in particular relates to a rectum washing device. The rectum washing device comprises a columnar flexible body structure, wherein the head of the columnar flexible body structure is a conical body, the tail part of the columnar flexible body structure is connected with a base, a strip-shaped groove is formed in the side walls of the columnar flexible body structure and the conical body at the head, the strip-shaped groove extends from the top end of the conical body to the bottom end of the columnar flexible body structure, at least one washing through hole is formed in the columnar flexible body structure along the direction parallel to the central axis of the columnar flexible body structure, the head of each washing through hole is formed in the conical body, the tail of each washing through hole communicates with the base, the folds of the rectum are pushed away through the edge wall of the strip-shaped groove, so that the cleaning effect is good, and the cleaning wastewater can be guided through the strip-shaped groove.