Watery diarrhea associated with pancreatic islet cell carcinoma.

A patient with severe watery diarrhea and a non-beta islet cell carcinoma of the pancreas producing five hormones (secretin, serotonin, enteroglucagon, vasoactive intestinal polypeptide, and pancreatic glucagon) is described. We have demonstrated massive pancreatic hypersecretion to be a major factor in this patient's diarrhea. Possible inter-relationships of the actions of five hormones present in excess in the patient are discussed.