Persistent Nausea and Abdominal Pain in a Patient With Delayed Gastric Emptying

A 46-year-old woman presents for the evaluation of persistent nausea and abdominal pain. The nausea is intermittent, usually postprandial, with occasional postprandial vomiting over the last year. She describes her abdominal pain as dull and occurring in the upper abdomen. Inconsistently, she experiences postprandial fullness and early satiety. She initially tried over-the-counter treatment with ranitidine and intermittent doses of acetaminophen for 6 weeks without relief. She has no other significant medical history and has not had prior surgeries. On physical examination, she appears well hydrated and vital signs are normal. Her abdomen is nondistended, but moderately tender in the epigastric region without voluntary guarding, rebound tenderness, or a succussion splash. The remainder of her physical examination is normal. Complete blood count with differential, complete metabolic profile, aminotransferase level, and amylase are normal. An abdominal obstruction series is normal. Upper endoscopy reveals distal esophageal erythema but is otherwise unremarkable with no food seen in the stomach. Antral mucosal biopsy is negative for Helicobacter pylori. A computerized tomography examination of the abdomen and pelvis is normal. Treatment with omeprazole is without benefit and her symptoms persist over the next 5 weeks. Treatment trials with tramadol (Ultram; Ortho McNeil Pharmaceutical, Titusville, NJ) as necessary for the pain and prochlorperazine (Compazine; GlaxoSmithKline, Research Triangle Park, NC) for the nausea are without help. Gastric emptying scintigraphy reveals delayed emptying of a radiolabelled egg sandwich meal with 68% retention at 2 hours after meal ingestion (normal, <60%) and 22% retention at 4 hours (normal, <10%). Metoclopramide (Reglan; Wyeth, Madison, NJ) 10 mg orally 4 times a day is started but discontinued because of the development of lethargy. How should this patient with delayed gastric emptying with major symptoms of abdominal pain and nausea be managed?