Tumor location:
(1) most often in the pancreas (may be malignant)
(2) small bowel carcinoid
(3) pheochromocytoma
(4) ganglioneuroma or ganglioneuroblastoma
Clinical features:
(1) watery diarrhea, up to several liters per day, which persists even when the patient is fasting
(2) dehydration
(3) weight loss
(4) colicy or crampy pain
(5) erythematous flushing of the head and/or trunk may occur in some
Laboratory features:
(1) serum hypokalemia
(2) high serum VIP levels
(3) stool osmolality can be explained by its sodium and potassium content
Differential diagnosis:
(1) cholera due to infection with a Vibrio species
(2) Zollinger-Ellison syndrome
(3) large colonic villous adenoma
(4) chronic laxative abuse
