Summary Gastroparesis and functional dyspepsia are common disorders that can cause chronic nausea and vomiting, early satiety, postprandial fullness, abdominal pain, and malnutrition that may require nutritional support. The broad objectives of this proposal is to improve our understanding of these disorders and advance the ability to diagnose and treat them. We propose to do this through three specific aims, as follows: Specific Aim 1: To successfully conclude ongoing studies that are currently being performed by the Gastroparesis Clinical Research Consortium. Specific Aim 2: To initiate a new Gastroparesis Registry with inclusion of a larger proportion of patients with idiopathic functional dyspepsia (GpR4 study) Specific Aim 3: To characterize the role of aberrant macrophage activation in humans with gastroparesis using pioglitazone (the “PIOGAS” study) Through these aims, we will be able to conclude important ongoing studies (Specific Aim 1), expand the spectrum of gastroparesis by understanding its relationship to functional dyspepsia (Specific Aim 2) and move closer to a cure for them (Specific Aim 3). Thus, our goals are highly translational and of immediate and profound impact for the target patient population.