 After the endoscopy, an aspiration catheter will be positioned in the duodenum. The position of the catheter will be briefly checked by fluoroscopy typically 2-3 seconds, however never more than 15 seconds. After positioning of the catheter, it is fixed to the subjects chin and heshe is asked to take place in a chair for the remainder of the experiment. For one hour, every 15 minutes duodenal fluids will be collected during fasted state. Next, a high resolution manometry catheter HRM will be placed in the gastric fundus to measure intragastric pressure and a perfusion tube OD 2 mm will be introduced through the nose and positioned in the stomach. After positioning of the catheters, they are fixed to the subjects chin and heshe is asked to take place in a chair for the remainder of the experiment. After a stabilization period of 15 minutes, intragastric infusion of the nutrient drink Nutridrink, Nutricia; 630 KJ, 6 g proteins, 18.4 g carbohydrates, and 5.8 g lipids per 100 mL will start at a constant speed of 60 mL per minute determined by an automated system using a peristaltic pump. Intragastric pressure will be measured with a 36-channel high resolution manometry system, through the intragastric manometry probe. At 1-minute intervals, the subjects will be asked to score their satiation using a graphic rating scale that combines verbal descriptors on a scale graded 0-5. At 5-minute intervals the volunteers will be asked to fill out a VAS for 11 dyspeptic symptoms. The intragastric infusion will be stopped as soon as the volunteers score maximally on one of the 11 epigastric symptoms or when a score of 5 is reached on their satiety scores. 10 minutes thereafter, the catheters will be disconnected and removed. After the nutrient drink infusion, duodenal fluids will be collected every 15 minutes for 1.5 hour during fed state. Finally, the last catheter is removed and the volunteer can go home. 