Intestinal motility is increased by

-Motilin is a polypeptide containing 22 amino acid residues that is secreted by enterochromaffin cells and Mo cells in the stomach,small intestine, and colon. It acts on G protein-coupled receptors on enteric neurons in the duodenum and colon and on injection produces contraction of smooth muscle in the stomach and intestines. Its circulating level increases at intervals of approximately 100 min in the interdigestive state, and it is a major regulator of the migrating motor complexes (MMCs) that control gastrointestinal motility between meals. -Substance P is found in endocrine and nerve cells in the gastrointestinal tract and may enter the circulation. It increases the motility of the small intestine. Reference ; GANONG'S REVIEW OF MEDICAL PHYSIOLOGY 23RD EDITION Pg 447,448