What diagnostic tests are recommended for a 19-year-old female with persistent, intermittent vomiting and bloating after meals?

Diagnostic Testing for a 19-Year-Old Female with Persistent, Intermittent Vomiting and Bloating After Meals

Gastric emptying scintigraphy is the recommended first-line diagnostic test for this patient with symptoms suggestive of gastroparesis. 1

Initial Evaluation

• Obtain a detailed history focusing on meal-related timing of symptoms, frequency and severity of vomiting episodes, and associated symptoms such as early satiety 1
• Perform physical examination to assess for dehydration, abdominal distention, and tenderness 1
• Rule out pregnancy with urine pregnancy test in any woman of childbearing age 2
• Basic laboratory tests should include:
  • Complete blood count to assess for anemia or infection 1
  • Comprehensive metabolic panel to evaluate electrolytes, renal and liver function 1
  • Thyroid-stimulating hormone level to rule out thyroid dysfunction 1

Specific Diagnostic Tests

First-Line Testing

• Gastric emptying scintigraphy: The gold standard test for diagnosing gastroparesis

  • Should be performed for at least 2 hours after ingestion of a radiolabeled meal (4-hour study preferred for increased sensitivity) 1
  • The radioisotope must be cooked into the solid portion of the meal 1
  • This test directly measures the rate of gastric emptying and can confirm delayed gastric emptying 1

• Upper endoscopy: To rule out structural causes of symptoms

  • Helps exclude mechanical obstruction, inflammatory conditions, or malignancy 1
  • Should be performed before other functional testing 1

Second-Line Testing

• Breath testing:

  • 13C-octanoate breath test can indirectly determine gastric emptying 1
  • Hydrogen breath testing for carbohydrate intolerances (lactose, fructose) if dietary triggers are suspected 1

• Antroduodenal manometry: Consider if initial tests are inconclusive

  • Provides information about coordination of gastric and duodenal motor function 1
  • Can differentiate between neuropathic and myopathic motility disorders 1
  • Helps diagnose rumination syndrome which can mimic vomiting 1

Diagnostic Algorithm Based on Alarm Features

• If alarm features are present (weight loss >10%, GI bleeding, family history of IBD):

  • Expedite upper endoscopy and imaging studies 1
  • Consider abdominal CT or MRI to rule out structural abnormalities 1

• If no alarm features:

  • Start with gastric emptying scintigraphy 1
  • If normal, consider:
    • Hydrogen breath testing for carbohydrate intolerances 1
    • Evaluation for small intestinal bacterial overgrowth (SIBO) with glucose or lactulose breath testing 1

Important Considerations

• Gastroparesis is a common cause of persistent postprandial vomiting and bloating in young adults, particularly females 1
• Functional dyspepsia frequently overlaps with gastroparesis symptoms and may require similar diagnostic approach 1
• Carbohydrate intolerances (lactose, fructose) are common and can cause similar symptoms; consider a 2-week dietary restriction trial before specialized testing 1
• Avoid routine use of abdominal imaging unless there are alarm symptoms or abnormal physical examination findings 1

Pitfalls to Avoid

• Do not perform gastric emptying studies for less than 2 hours as shorter durations are inaccurate for determining gastroparesis 1
• Avoid performing tests while the patient is taking medications that affect gastric motility (prokinetics, opioids, anticholinergics) 1
• Do not assume functional dyspepsia without first ruling out gastroparesis with objective testing 1
• Remember that normal gastric emptying with normal antroduodenal manometry strongly suggests that antral motor dysfunction is not the cause of symptoms 1