8th February 2024

A 57-year-old female presents with watery diarrhoea.

A 57-year-old female presents with watery diarrhoea. She has passed approximately 1.2L of stool daily for the past five months. She has associated weight loss of 8kg and facial flushing. The stools are watery without any blood or mucous mixed into the stool. Bloods show raised urea, raised creatinine, hypokalaemia and metabolic acidosis. 

CT scans have revealed a pancreatic mass. 

Given the likely hormone responsible, which part of the GI tract typically produces this hormone?