proc·tol·o·gy 
(prŏk-tŏlə-jē)
(prŏk-tŏlə-jē)n.
The branch of medicine that deals with the diagnosis and treatment of disorders affecting the colon, rectum, and anus.
[Greek prōktos, anus + -LOGY.]
proc′to·logic (-tə-lŏjĭk), proc′to·logi·cal (-ĭ-kəl) adj.
proc′to·logi·cal·ly adv.
proc·tolo·gist n.