Tenesmus \Te*nes"mus\, n. [NL., fr. Gr. ?, fr. ? to stretch: cf. L. tenesmos.] (Med.) An urgent and distressing sensation, as if a discharge from the intestines must take place, although none can be effected; -- always referred to the lower extremity of the rectum. {Vesical tenesmus}, a similar sensation as to the evacuation of urine, referred to the region of the bladder.