Tenesmus commonly occurs when there is inflammation in the rectum (the last few inches of the colon where stool is stored until it is time to have a bowel movement).
Tenesmus refers to cramping rectal pain. Tenesmus gives you the feeling that you need to have a bowel movement, often urgently, when there is not actually anything there to pass. Some people refer to the pain as feeling like spasm's, or even throbbing. When you have tenesmus, you might strain harder to produce only a small amount of stool during bowel movements.
Tenesmus is commonly a symptom of Ulcerative Colitis, Crohn's Disease and in a jpouch, Cuffitis.