Diagnostic Approach for Gastroparesis

Initial Evaluation and Diagnostic Testing

The American Gastroenterological Association recommends obtaining a detailed history focusing on meal-related timing of symptoms, frequency and severity of vomiting episodes, and associated symptoms such as early satiety in patients with suspected gastroparesis 1
A physical examination should be performed to assess for dehydration, abdominal distention, and tenderness in patients with symptoms suggestive of gastroparesis 1
Basic laboratory tests, including complete blood count to assess for anemia or infection, comprehensive metabolic panel to evaluate electrolytes, renal and liver function, and thyroid-stimulating hormone level to rule out thyroid dysfunction, are recommended for patients with suspected gastroparesis 3, 4, 5

Gastric emptying scintigraphy is the gold standard test for diagnosing gastroparesis and should be performed for at least 2 hours after ingestion of a radiolabeled meal 1, 2
Upper endoscopy is recommended to rule out structural causes of symptoms, such as mechanical obstruction, inflammatory conditions, or malignancy, and should be performed before other functional testing 4, 5, 6
Breath testing, including 13C-octanoate breath test and hydrogen breath testing for carbohydrate intolerances, may be considered as second-line testing for patients with suspected gastroparesis 2, 5, 6
Antroduodenal manometry can provide information about coordination of gastric and duodenal motor function and can differentiate between neuropathic and myopathic motility disorders 1, 2

If alarm features are present, such as weight loss >10%, GI bleeding, or family history of IBD, expedited upper endoscopy and imaging studies are recommended 5, 6
If no alarm features are present, gastric emptying scintigraphy should be started, followed by consideration of hydrogen breath testing for carbohydrate intolerances or evaluation for small intestinal bacterial overgrowth (SIBO) if normal 1, 2, 5, 6

Gastroparesis is a common cause of persistent postprandial vomiting and bloating in young adults, particularly females, and functional dyspepsia frequently overlaps with gastroparesis symptoms 1, 2
Carbohydrate intolerances, such as lactose or fructose intolerance, are common and can cause similar symptoms, and a 2-week dietary restriction trial may be considered before specialized testing 5
Routine use of abdominal imaging should be avoided unless there are alarm symptoms or abnormal physical examination findings 5, 6