Idiopathic Dumping Syndrome in Patients Presenting with Chronic Unexplained Nausea

Abstract

Introduction: Dumping syndrome is a well—known complication after gastric surgery. However, limited literature exists on idiopathic dumping syndrome. Our aim is to investigate the clinical characteristics of non—surgical patients with rapid gastric emptying who present with unexplained chronic nausea. Methods: A retrospective study was conducted on patients who had severe rapid gastric emptying, defined as gastric retention <30% at one hour during a four—hour isotope—labeled solid meal test. These patients were identified by chart review and were seen in a Neurogastroenterology Clinic at an academic institution between January 2011 and December 2017 for nausea and other unexplained gastrointestinal symptoms. Results: Forty—six patients were identified with severe rapid gastric emptying; sixteen were excluded due to previous gastric surgeries. The remaining thirty non—surgical patients (50% females, mean age 49 years, mean BMI 28) had a mean gastric retention of 19% (range 2% to 30%) at one hour. Thirteen (43%) had diabetes, and nine (30%) were insulin dependent. Six patients (20%) had a previous diagnosis of gastroparesis. All patients presented with unexplained nausea, fifteen (50%) had early satiety, and fifteen (50%) had bloating. Variations in bowel habits were reported as follows: 26% with diarrhea, 27% with constipation, 10% with diarrhea and constipation, and 27% with normal bowel movements. Sixteen (53%) patients had electrogastrogram tests: 69% had poor water load satiety test (ingested <557 mL in five min), 13% had tachygastria, 25% had bradygastria, 19% had mixed tachygastria and bradygastria, and 44% were normal. Five patients (17%) had positive breath tests for small bowel bacterial overgrowth. Conclusion: 1. Patients with severe idiopathic rapid gastric emptying may present with nausea and gastroparesis—like symptoms rather than vasomotor symptoms and diarrhea typically seen in postsurgical dumping syndrome; 2. Over half of the patients had risk factors for abnormal gastric motility, such as diabetes, poor water load satiety tests, and gastric dysrhythmias, which may contribute to altered emptying rates; 3. Physiological mechanisms underlying rapid gastric emptying warrants further investigations; and 4. Rapid gastric emptying should be considered in patients who present with chronic unexplained nausea without previous gastric surgeries.