Effective clinical therapy to augment intestinal absorption of water and electrolytes does not exist; the gut hormone, peptide YY (PYY), is a potent proabsorptive agent in animal models. The purpose of our study was to evaluate the effects of two novel PYY analogs, BIM-43073D and BIM-43004C, on intestinal absorption. Dogs with ileal Thiry-Vella fistulae (TVF) were treated with either PYY, BIM-43073D, or BIM-43004C. Administration of BIM-43073D significantly increased water and sodium absorption over baseline and maintained this level of increased absorption for a longer duration than an equimolar dose of PYY. Administration of BIM-43004C significantly increased sodium and water absorption over baseline at a level equal to that of PYY. The novel PYY analogs, BIM-43073D and BIM-43004C, are effective proabsorptive agents with BIM-43073D producing more sustained effects than PYY. These compounds may be clinically useful in the treatment of gut malabsorption in conditions such as cholera, Crohn's disease, and the short-bowel syndrome.