Tenesmus refers to cramping rectal pain. Tenesmus gives you the feeling that you need to have a bowel movement, even if you already have had one. When you have tenesmus, you might strain harder to produce only a small amount of stool during bowel movements
Any number of inflammatory bowel diseases (IBDs) can cause tenesmus. An IBD causes long-term inflammation in all or some parts of your gastrointestinal (GI) tract, or digestive tract. The most common forms of IBD are Crohn’s disease and ulcerative colitis.
Both Crohn’s disease and ulcerative colitis cause you to have ulcerations in your GI tract. These ulcers cause scarring along the walls of your digestive organs. This scarring can make it harder for you to pass your stool normally, which can lead to tenesmus. If you have Crohn’s disease, these ulcerations can spread throughout your GI tract. In the case of ulcerative colitis, these ulcers are located only in your colon and rectum.
What causes these IBDs is not known. Both genetics and the immune system are thought to play a part.