VIPR1 and neoplasm: Hypersecretion of VIP by this ectopic tumor causes large-volume watery diarrhea, hypokalemia, and achlorhydria known as pancreatic cholera, the Verner–Morrison syndrome, or the WDHA syndrome62, due to the action of VIP on VPAC1 receptors in the intestinal mucosa that increases Cl– and water movement into the intestinal lumen58.