VPAC1 KO mice exhibit impaired neonatal growth and increased post-weaning death due to intestinal obstruction and hypoglycemia, histologically with increased mucosal cell proliferation, bowel wall thickening, and smaller pancreatic islet size48, suggesting that VPAC1 is essential for the normal development of the intestinal tract and the endocrine pancreas. Here, VIPR1 is linked to intestinal obstruction.