The present invention is directed to polynucleotides, polypeptides, peptides, variants and uses thereof for novel peptide fragments which have homology to motilin. Tissue distribution of the mRNA for the novel polypeptide fragment is specific to the stomach, small intestine and pancreas. Binding of the peptide fragment has been shown in kidney and small intestine. The present invention further includes agonists, antagonists, variants, antibodies and host cells expressing the cDNA encoding the novel SGIP peptide.