This invention pertains to polypeptides, other than motilin, having gastrointestinal motor stimulating activity and represented by the formula: ##STR1## wherein A and D are lipophilic aliphatic or alicyclic amino acids; B is L-proline or L-alanine; E is an aromatic, lipophilic aliphatic, or alicyclic amino acid; F is an aromatic or heteroaromatic amino acid; G is glycine or D-alanine; H is L-glutamic acid or L-glutamine; I is L-glutamine, L-glutamic acid, or L-alanine; J is a direct bond or is selected from, inter alia Z, Z-Leu, Z-Leu-Gln, Z-Leu-Gln-Glu (SEQ ID NO:2) or Z-Leu-Gln-Glu-Lys (SEQ ID NO:3), wherein Z is, inter alia, arginine, D-arginine, D-homoarginine, or D-lysine, and further wherein the amino acids represented by A, D, E and F are L-stereoisomers; R.sub.1 is lower-alkyl or allyl; R.sub.2 is hydrogen, lower-alkyl, propargyl, or allyl; R.sub.3 is hydrogen, lower-alkyl, and allyl; R.sub.4 is lower-alkyl, cycloalkyl, heteroaryl, unsubstituted aryl, and aryl substituted by halogen, hydroxy, or lower-alkoxy; R.sub.5 is --CH.sub.2 CONH.sub.2, aminoalkyl, or guanidinoalkyl; R.sub.6 is --COOH or --CONH.sub.2 ; and m is 0 or 1, and the asymmetric carbon represented by * may be D or L configuration, with certain specified provisos.