Patients with long standing diabetes, usually for more than 5 years, could develop decreased motility of the stomach, leading to delayed gastric emptying, which will present as abdominal fullness after meals, early satiety, and upper abdominal discomfort. This is called diabetic gastroparesis and is diagnosed by carrying out nuclear medicine solid and liquid phase gastric emptying studies, and an endoscopy. In the first instance I would recommend an endoscopy and eradication of Helicobacter pylori, if positive.