Chan Fung-Chi

A triad assassin is sent to kill a female witness to a murder only to fall in love with her instead.

A cop suffering from "posterior ulcers" tries to catch a serial killer who seeks out victims with medical problems. One suspect is a man who makes pies from guts, which the cop inadvertantly eats. Eventually the hero cop finds himself tied to an operating table with the killer preparing to deal with his "posterior ulcers"!