An 84-year-old woman was hospitalised with a 1-year history of aqueous diarrhoea, with 10–15 episodes a day, particularly during daytime and after meals. She also mentioned anorexia, weight loss (20% of body weight) and epigastric discomfort. There was no history of fever, vomiting or blood or mucus in the stools. She had a history of multiple surgical interventions, including a Nissen fundoplication, a left hemicolectomy due to diverticular disease, a gastrojejunostomy with adhesiolysis due to intestinal subocclusion and a cholecystectomy, the last one 6 years before. She had an extensive outpatient investigation with negative microbiological stool tests, including Clostridium difficile, normal faecal calprotectin and elastase, normal thyroid function, negative coeliac antibodies and no vitamin or nutrient deficiency. …