Input the retention percentages from the GES report to visualize the severity classification.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Diagnosis of gastroparesis in patients with nausea, vomiting, early satiety, or bloating
Evaluation of "dumping syndrome" (rapid gastric emptying)
Monitoring response to prokinetic therapy (Metoclopramide, Erythromycin, Prucalopride)
Pre-operative evaluation for gastric peroral endoscopic myotomy (G-POEM) or pyloroplasty
Standardization Requirement
Accurate GES requires the "Consensus Egg Meal": 2 egg-whites (or Egg Beaters), 2 slices of bread/toast, jam, and water (approx. 255 kcal). Use of non-standard meals significantly limits interpretation and validity.
Patient Preparation
Fasting for ≥ 6 hours
Stop prokinetics and opiates for ≥ 48-72 hours prior to the study
Optimal glucose control in diabetics (ideally < 275 mg/dL on the day of study); severe hyperglycaemia slows emptying and causes false positives
Section 2
Formula & Logic
Standard Thresholds (Solid Meal)
1 Hour
Abnormal if > 90% retained
2 Hours
Abnormal if > 60% retained
4 Hours
Abnormal if > 10% retained
Rapid Gastric Emptying Thresholds
1 Hour
Rapid if < 30% retained
2 Hours
Rapid if < 50% retained
Severity Grading (at 4 Hours)
01
Mild: 11–15% gastric retention.
02
Moderate: 16–35% gastric retention.
03
Severe: > 35% gastric retention.
Section 3
Pearls/Pitfalls
Why the 4-Hour Mark is Essential
Shorter studies (1 or 2 hours) are significantly less sensitive. Up to 30% of patients with gastroparesis will have a normal 2-hour scan but show significant retention at the 4-hour mark. 4-hour monitoring is the global diagnostic standard.
Liquid vs. Solid Emptying
Solid emptying is typically affected first in gastroparesis. Combined solid and liquid scans may be useful in patients with severe symptoms but normal solid-only scans, or when assessing surgical complications.
Clinical Pearls
Diabetic gastroparesis often presents with more severe retention at 4 hours compared to idiopathic cases
A normal GES in a highly symptomatic patient should prompt investigation for Functional Dyspepsia (Roman IV) or Gastric Accommodation disorders
Gastric emptying rate is highly variable day-to-day; borderline results may benefit from repeat testing if clinical suspicion is high
Section 4
Next Steps
Management Pathways
01
Delayed Emptying: High-protein, low-fiber, low-fat small frequent meals; Trial of prokinetics; Screen for secondary causes (Diabetes, Scleroderma, Post-viral).
02
Rapid Emptying: Dietary modifications (complex carbs, avoid sugar); Screen for Post-Nissen or Post-Gastrectomy Dumping syndrome.
Complementary Motility Tools
GCSI (Gastroparesis Cardinal Symptom Index)
Wireless Motility Capsule (SmartPill)
Antroduodenal Manometry Interpreter
Section 5
Evidence Appraisal
Consensus Standards
Consensus recommendations for gastric emptying scintigraphy: a joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine.
Abell TL et al. • Journal of Nuclear Medicine Technology. 2008;36(1):44-54. Establishing the 4-hour standard and egg-meal protocol.
The the American Neurogastroenterology and Motility Society (ANMS) and the Society of Nuclear Medicine (SNM) joined forces in 2008 to end the "wild west" of gastric emptying, where every hospital had its own meal (e.g., oatmeal, pancakes, bacon) and varied thresholds. The 2008 consensus finally gave clinicians a universal language.
