antiperistaltic /-per′əstal″tik/ [Gk, anti + peristellein, to wrap around] , 1. pertaining to a substance that inhibits or diminishes peristalsis. 2. an antiperistaltic agent. Opioids, such as paregoric, diphenoxylate hydrochloride, and loperamide hydrochloride, provide symptomatic relief of diarrhea. Anticholinergics reduce spasms of intestinal smooth muscle and are frequently prescribed to decrease excessive GI motility.