A pharmaceutical composition for inducing contractile motility of the gastrointestinal tract in humans and animals, comprising as active ingredient 8,9-anhydroerythromycin 6,9-hemiketals, anhydroerythromycins, derivatives thereof and/or pharmaceutically acceptable salts thereof, in association with a pharmaceutically acceptable carrier or excipient. The active compounds may be produced by chemical modification of erythromycin and exhibit no or little antimicrobial activity. By administering the present composition to humans and animals, contractile motility of the gastrointestinal tract similar to the motility occurring naturally under normal conditions may be effectively induced.