Gastroparesis
Summary
Gastroparesis is a syndrome of delayed gastric emptying in the absence of mechanical obstruction. The most common causes are diabetes mellitus (autonomic neuropathy), post-surgical (vagal injury), and idiopathic. Patients present with nausea, vomiting (often of undigested food hours after eating), early satiety, bloating, and abdominal pain. Diagnosis is confirmed by gastric emptying scintigraphy. Treatment involves dietary modification, prokinetic agents (metoclopramide, domperidone, erythromycin), and in refractory cases, gastric electrical stimulation or enteral feeding.
Key Facts
- Definition: Delayed gastric emptying without mechanical obstruction
- Major Causes: Diabetic (30%), Idiopathic (35%), Post-surgical (13%)
- Symptoms: Nausea, vomiting (undigested food), early satiety, bloating
- Diagnosis: Gastric emptying study (scintigraphy)
- Treatment: Diet modification, Prokinetics (Metoclopramide, Domperidone, Erythromycin)
- First Step: Exclude mechanical obstruction (OGD)
Clinical Pearls
"Exclude Obstruction First": Gastroparesis is a diagnosis of exclusion. Always perform upper GI endoscopy to rule out mechanical gastric outlet obstruction before diagnosing gastroparesis.
"Optimise Glucose Control": Hyperglycaemia directly impairs gastric motility. Excellent glycaemic control is a fundamental part of managing diabetic gastroparesis.
"Erythromycin Works Acutely, Tachyphylaxis Occurs": Erythromycin is a potent prokinetic (motilin agonist) but loses effectiveness within 4 weeks due to receptor downregulation.
"Diabetic Gastroparesis = Autonomic Neuropathy": If diabetic gastroparesis is present, look for other signs of autonomic neuropathy (postural hypotension, anhidrosis, erectile dysfunction).
Incidence
- Prevalence: 25-55 per 100,000 population
- More common in women (4:1)
Demographics
- Peak age: 20-50 years
- More common in Type 1 diabetes than Type 2
- Female predominance
Causes
| Cause | Frequency | Notes |
|---|---|---|
| Diabetic | 30% | Autonomic neuropathy; correlates with duration and control |
| Idiopathic | 35% | May follow viral illness; often young women |
| Post-surgical | 13% | Vagotomy, fundoplication, bariatric surgery |
| Medications | 10% | Opioids, anticholinergics, GLP-1 agonists |
| Connective tissue | Rare | Scleroderma, SLE |
| Neurological | Rare | Parkinson's, MS |
Normal Gastric Emptying
- Gastric accommodation and trituration
- Antral contractions
- Pyloric relaxation
- Duodenal receptivity
- Coordinated by vagus nerve and enteric nervous system
Mechanisms of Gastroparesis
| Mechanism | Cause |
|---|---|
| Vagal neuropathy | Diabetes, surgery |
| Loss of ICC cells | Interstitial cells of Cajal (pacemaker cells) |
| Smooth muscle dysfunction | Connective tissue disease |
| Central dysregulation | Post-viral, idiopathic |
Diabetic Gastroparesis
- Autonomic neuropathy (vagal damage)
- Hyperglycaemia directly slows emptying (acute effect)
- Loss of ICC cells
- Associated with other diabetic complications
Symptoms
| Feature | Notes |
|---|---|
| Nausea | Most common symptom (>0%) |
| Vomiting | Undigested food, hours after eating |
| Early satiety | Feeling full after small amounts |
| Bloating | Postprandial abdominal distension |
| Abdominal pain | Upper abdominal |
| Weight loss | If prolonged |
Timing
Severity Grading (Abell Classification)
| Grade | Symptoms | Management |
|---|---|---|
| Mild | Intermittent, controlled | Diet + PRN antiemetics |
| Moderate | Frequent, medications needed | Regular prokinetics |
| Severe | Refractory, hospitalisations | IV fluids, enteral feeding, surgery |
General
- Weight loss / malnutrition (severe cases)
- Dehydration (if vomiting significant)
Abdominal
- Epigastric distension
- Succussion splash (fluid in stomach when shaking)
- No peritonism
Diabetic Complications
- Signs of autonomic neuropathy
- Retinopathy, peripheral neuropathy
First-Line
| Test | Purpose |
|---|---|
| Upper GI Endoscopy (OGD) | EXCLUDE mechanical obstruction (essential) |
| Blood tests | Glucose (HbA1c), U&E, LFTs, nutritional markers |
Diagnostic Test
- Gastric Emptying Scintigraphy: Gold standard
- Patient eats radiolabelled meal
- Gastric retention measured at 2 and 4 hours
- Abnormal: >60% at 2h or >10% at 4h
Alternative Tests
- Wireless motility capsule: Measures gastric transit
- 13C-breath test: Simpler, less validated
Exclude
- Mechanical obstruction (OGD, CT)
- Metabolic causes (hypothyroidism, adrenal insufficiency)
- Drug causes (opioids, GLP-1 agonists)
Management Approach
┌──────────────────────────────────────────────────────────┐
│ GASTROPARESIS MANAGEMENT │
├──────────────────────────────────────────────────────────┤
│ │
│ STEP 1: EXCLUDE OBSTRUCTION (OGD) │
│ │
│ STEP 2: TREAT UNDERLYING CAUSE │
│ • Optimise glycaemic control (diabetic) │
│ • Stop causative medications (opioids) │
│ │
│ STEP 3: DIETARY MODIFICATION │
│ • Small, frequent meals │
│ • Low fat, low fibre (easier to empty) │
│ • Liquid/pureed consistency if severe │
│ • Avoid carbonated drinks │
│ │
│ STEP 4: PROKINETICS │
│ • Metoclopramide 10mg TDS AC (risk: tardive dyskinesia) │
│ • Domperidone 10mg TDS AC (risk: QT prolongation) │
│ • Erythromycin 40-250mg TDS AC (tachyphylaxis) │
│ │
│ STEP 5: ANTIEMETICS │
│ • Ondansetron, Prochlorperazine │
│ │
│ STEP 6: REFRACTORY CASES │
│ • Gastric electrical stimulation (Enterra) │
│ • NJ/PEG-J feeding if nutrition failing │
│ • Pyloroplasty / G-POEM │
│ • Gastric resection (last resort) │
│ │
└──────────────────────────────────────────────────────────┘
Prokinetic Agents
| Drug | Dose | Mechanism | Cautions |
|---|---|---|---|
| Metoclopramide | 10mg TDS | D2 antagonist + 5HT4 agonist | Tardive dyskinesia (limit <12 weeks) |
| Domperidone | 10mg TDS | D2 antagonist (peripheral) | QTc prolongation, cardiac death |
| Erythromycin | 40-250mg TDS | Motilin agonist | Tachyphylaxis by 4 weeks |
| Prucalopride | 1-2mg OD | 5HT4 agonist | Off-label for gastroparesis |
Of Gastroparesis
- Malnutrition and weight loss
- Dehydration
- Bezoar formation (undigested food mass)
- Poor glycaemic control (unpredictable absorption)
- Frequent hospitalisations
- Poor quality of life
Of Treatment
- Metoclopramide: Tardive dyskinesia, extrapyramidal effects
- Domperidone: QT prolongation, sudden cardiac death
- Erythromycin: GI upset, drug interactions
Natural History
- Chronic, relapsing condition
- Post-viral idiopathic may improve
- Diabetic gastroparesis often progressive
With Treatment
- Many achieve symptom control with diet + prokinetics
- 25-30% have refractory symptoms
Prognosis by Cause
| Cause | Prognosis |
|---|---|
| Post-viral | May resolve spontaneously |
| Diabetic | Chronic, progressive |
| Idiopathic | Variable |
| Post-surgical | May improve over time |
Key Guidelines
- ACG Clinical Guideline: Management of Gastroparesis (2013)
- BSG Recommendations
Key Evidence
Prokinetics
- Metoclopramide and domperidone have short-term efficacy
- Long-term use limited by side effects
Gastric Electrical Stimulation
- Reduces symptoms and hospitalisations in refractory cases
- Limited evidence for improvement in gastric emptying
What is Gastroparesis?
Gastroparesis means your stomach empties food more slowly than normal. It's like your stomach muscles aren't working properly, so food stays in your stomach for too long.
What Causes It?
- Diabetes: Nerve damage from high blood sugars
- After surgery: Especially stomach operations
- Unknown: Sometimes no cause is found
What Are the Symptoms?
- Feeling sick (nausea)
- Vomiting, sometimes several hours after eating
- Feeling full after only a few bites
- Bloating
- Tummy pain
How is it Diagnosed?
After ruling out blockages with a camera test (endoscopy), you may have a gastric emptying study - you eat a meal with a small amount of radioactive tracer, and a scanner measures how quickly your stomach empties.
How is it Treated?
- Diet changes: Smaller, more frequent meals; low-fat, low-fibre foods
- Medications: Tablets to help your stomach empty faster (metoclopramide, domperidone, erythromycin)
- Good diabetes control: Essential if diabetic
- In severe cases, special feeding tubes or surgery may be needed
Primary Guidelines
- Camilleri M, et al. Clinical Guideline: Management of Gastroparesis. Am J Gastroenterol. 2013;108(1):18-37. PMID: 23147521
Key Studies
- Parkman HP, et al. Gastroparesis and functional dyspepsia: excerpts from the AGA/ANMS review. Neurogastroenterol Motil. 2010;22(2):113-133. PMID: 20003077
- McCallum RW, et al. Gastric electrical stimulation with Enterra therapy improves symptoms from diabetic gastroparesis. J Gastrointest Surg. 2010;14(3):468-475. PMID: 20066545