A peptide agonist of the guanylate cyclase C receptor (Ki = 16.4 nM in a radioligand binding assay using mouse intestinal mucosa); stimulates fluid secretion and cGMP concentration in jejunal loops isolated from wild-type mice but not guanylate cyclase C receptor null mice; increases intestinal transit in wild-type mice when administered at a dose of 100 μg/kg; reduces the number of phosphorylated ERK-positive dorsal horn neurons in the thoracolumbar spinal cord, a marker of nociceptive signaling, following noxious colorectal distension and mechanical hypersensitivity in a mouse model of TNBS-induced colitis