Relationships of gastric emptying, appetite and gastrointestinal hormones following consumption of solid and liquid food in people who have had gastric bypass surgery for treatment of obesity

Following Roux-en-Y gastric bypass, a type of surgery to induce weight loss in individuals who are obese, the size of the stomach is considerably reduced and food passes through to the small intestines faster. When food passes through the small intestines, various ‘hormones’ that are thought to assist with weight loss are released and enter the bloodstream. While this seems to be a useful effect, a proportion of patients can experience complications such as having an abnormally low blood sugar level (hypoglycaemia) or low blood pressure after eating. We think this may happen due to these patients producing more of these ‘hormones’ than others. This study will evaluate the movement of solid and liquid food that have been eaten and how it affects the amount of ‘hormones’ produced. Given the smaller size of the stomach, liquids could ‘wash down’ the solid food and increase the amount of ‘hormones’ produced. Learning about how the passage of solid and liquid food through the small intestine changes the amount of ‘hormones’ produced will lead to a better understanding these complications and help us develop new and more effective treatment. This information may also help us improve the dietary advice provided to patients who have had this surgery.