Abstract: This invention pertains to cyclic polypeptides having gastrointestinal motor stimulating activity which may be represented by formula (1): ##STR1## including optically active isomeric forms and the pharmaceutically acceptable acid addition salts thereof, wherein groups A and D are linked to from a cyclic structure; and R.sub.1 is lower alkyl; R.sub.2 is hydrogen or lower alkyl; R.sub.3 is hydrogen or lower alkyl; R.sub.4 is phenyl or substituted phenyl, wherein the phenyl group may be substituted with one or more substituents selected from the group consisting of halogen, hydroxy, and lower alkoxy; R.sub.5 is --OH or --NH.sub.2 ; A is selected from the group consisting of L-glutamic acid, L-aspartic acid, L-lysine, L-ornithine, and L-2,4-diaminobutyric acid; B is L-alanine or L-glutamine; C is L-arginine or D-arginine; D is selected from the group consisting of L-lysine, L-ornithine, L-2,4-diaminobutyric acid, L-glutamic acid, and L-aspartic acid; E is a direct bond between group D and group R.sub.