[医] 里急后重, 下坠

[ noun ]
painful spasm of the anal sphincter along with an urgent desire to defecate without the significant production of feces; associated with irritable bowel syndrome
<noun.state>

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.