Gastrointestinal complications of diabetes include gastroparesis, intestinal enteropathy (which can cause diarrhea, constipation, and fecal incontinence), and nonalcoholic fatty liver disease. Patients with gastroparesis may present with early satiety, nausea, vomiting, bloating, postprandial fullness, or upper abdominal pain. The diagnosis of diabetic gastroparesis is made when other causes are excluded and postprandial gastric stasis is confirmed by gastric emptying scintigraphy. Whenever possible, patients should discontinue medications that exacerbate gastric dysmotility; control blood glucose levels; increase the liquid content of their diet; eat smaller meals more often; discontinue the use of tobacco products; and reduce the intake of insoluble dietary fiber, foods high in fat, and alcohol. Prokinetic agents (e.g., metoclopramide, erythromycin) may be helpful in controlling symptoms of gastroparesis. Treatment of diabetes-related constipation and diarrhea is aimed at supportive measures and symptom control. Nonalcoholic fatty liver disease is common in persons who are obese and who have diabetes. In persons with diabetes who have elevated hepatic transaminase levels, it is important to search for other causes of liver disease, including hepatitis and hemochromatosis. Gradual weight loss, control of blood glucose levels, and use of medications (e.g., pioglitazone, metformin) may normalize hepatic transaminase levels, but the clinical benefit of aggressively treating nonalcoholic fatty liver disease is unknown. Controlling blood glucose levels is important for managing most gastrointestinal complications.