Rectal tenesmus is a feeling of incomplete defecation. It is the sensation of inability or difficulty to empty the bowel at defecation, even if the bowel contents have already been evacuated. Tenesmus indicates the feeling of a residue, and is not always correlated with the actual presence of residual fecal matter in the rectum.
It is frequently painful and may be accompanied by involuntary straining and other gastrointestinal symptoms. Tenesmus has both a nociceptive and a neuropathic component.
Vesical tenesmus refers to the feeling of incomplete emptying of the bladder following urination. it is caused by urogenital diaphragm muscle spasms.
When the word tenesmus is used without modification, it usually refers to rectal tenesmus.