Plasma secretin before and after gastroplasty for morbid obesity.

Fasting and postprandial plasma secretin levels were measured in 11 patients before and 3 months after gastroplasty for morbid obesity. Ingestion of a meal significantly increased plasma secretin both before and after gastroplasty (P less than 0.05). After gastroplasty there was an additional but insignificant increase in postprandial plasma secretin. Secretin has evidently no major role in the development of early satiety after gastroplasty and the lack of significantly changed secretin levels after operation indicates an unchanged intraduodenal pH.