VIPoma /vipō″mə/ , a type of pancreatic tumor that causes changes in secretion of vasoactive intestinal polypeptide (VIP). VIP causes dilation of blood vessels throughout the body and secretion of fluid and salt in the intestinal tract, resulting in diarrhea. The VIP effects mimic the symptoms of cholera (severe diarrhea, hypokalemia, and hypochlorhydria) and can result in death from dehydration and subsequent kidney failure if treatment is not begun early. See also vasoactive intestinal polypeptide.