The rectum is about eight inches long, and it’s function is to keep bowel waste in place until you are ready to go to the bathroom. It connects to the sigmoid colon and to the anal canal.

Common rectum and colon disorders

Colorectal/rectum cancer
Colorectal cancer is cancer that starts in the colon or the rectum. Colon cancer and rectal cancer have many features in common. They are discussed together in this document except for the section about treatment, where they are discussed separately.

Hemorrhoids are enlarged veins near the lower end of the rectum or outside the anus.

Rectal bleeding
Irritation of the rectum from diarrhea, constipation, hemorrhoid or an anal fissure can cause a small amount of bright red blood on the surface of the stool or on the toilet paper. This type of bleeding can cause pain during a bowel movement and does not make the toilet water bloody.