The difficulties involved in feeding critically ill patients by the enteral route are well recognised. Often it is gastric emptying that is the problem. Nguyen et al. [34] have investigated the absorption of fat and carbohydrates in the small intestine in relation to motility following surgical repair of abdominal aortic aneurysms. Motility was impaired as compared to controls. This resulted in reduced absorbtion of both fat and carbohydrate. Over time, it was demonstrated that the reduced fat absorbtion was more prolonged after the surgical procedure. This technique opens up interesting possibilities and seems suited for use in evaluations of other groups of critically ill patients, and perhaps to guide the composition of enteral formulations as suggested by the authors.