 The Rome III criteria defined functional dyspepsia FD as the presence of symptoms thought to originate in the gastroduodenal region, in the absence of any organic, systemic or metabolic disease that readily explains the complaints. FD is extremely common, affecting up to 15-20 of the population and is associated with significantly decreased quality of life and substantial healthcare costs. The available treatment options for FD are of limited effectiveness, which reflects the poorly understood pathogenesis. Studies indicate that FD is a heterogeneous disorder, in which different pathophysiological mechanisms underlie specific symptom patterns. Traditionally, gastric abnormalities such as impaired accommodation, delayed emptying and hypersensitivity have been believed to be involved in the pathophysiology of FD. More recent studies have suggested that also a number of duodenal abnormalities can be responsible for the generation of symptoms, like increased sensitivity to duodenal acid, increased sensitivity to duodenal lipids and low-grade mucosal inflammation. 