Vipomas are tumours which secrete vasoactive intestinal peptide (VIP) and present with severe watery diarrhoea (the Verner and Morrison syndrome). The tumours are usually pancreatic in adults and originate in the sympathetic nervous system in children (neuroblastoma). The diagnosis is confirmed by the finding of raised plasma VIP. The treatment of choice is surgical excision of the tumour which leads to the regression of the watery diarrhoea.