giant peristaltic contraction, a propulsive contraction of the bowel that normally occurs periodically in the distal small intestine and colon. The contractions are 1.5 to 2 times larger than normal in amplitude and 4 to 6 times longer in duration than usual. In certain disease states, giant peristaltic contractions may start in the proximal small intestine and proceed uninterrupted. They may also be induced by a variety of stimuli including certain antibiotics, radiation therapy, and parasitic infections.
