Abdominal Bloating (Abdominal Distension)

Overview

Abdominal bloating (or distension) refers to the sensation or visible increase in abdominal size due to accumulation of gas, fluid, or altered motility. It is a symptom, not a disease, and can arise from:

• Functional gastrointestinal disorders (irritable bowel syndrome, functional dyspepsia).

• Dietary causes (carbonated drinks, high-FODMAP foods, lactose intolerance).

• Medical conditions (ascites, bowel obstruction, gastroparesis, celiac disease).

• Medications (opioids, anticholinergics).

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Treatment Options

1. Lifestyle and Dietary Measures

• Avoid carbonated beverages, chewing gum, high-FODMAP foods.

• Eat smaller, frequent meals.

• Increase dietary fiber gradually (except in bowel obstruction).

• Encourage physical activity to enhance motility.

2. Pharmacological Therapy (Symptomatic Relief)

• Antiflatulents:

  • Simethicone: 40–125 mg PO after meals and at bedtime as needed.

• Prokinetics (for motility disorders):

  • Metoclopramide: 5–10 mg PO up to QID before meals and at bedtime (max 40 mg/day).

  • Domperidone: 10 mg PO TID before meals (not available in some countries).

• Antispasmodics (for IBS-related bloating and cramps):

  • Hyoscine butylbromide: 10–20 mg PO TID as needed.

  • Dicyclomine: 10–20 mg PO q6–8h.

• Laxatives (if constipation-related):

  • Polyethylene glycol (PEG 3350): 17 g dissolved in water once daily.

  • Lactulose: 15–30 mL PO daily, titrated to effect.

• Antidiarrheals (if diarrhea-related):

  • Loperamide: 2 mg PO after each loose stool, max 16 mg/day.

3. Specific Therapies (When Underlying Cause Identified)

• Lactose intolerance:

  • Lactase enzyme supplements: 3000–9000 units PO with first bite of dairy.

• Small intestinal bacterial overgrowth (SIBO):

  • Rifaximin: 400 mg PO TID for 10–14 days.

• Celiac disease: Strict gluten-free diet.

• Ascites:

  • Spironolactone: 100 mg PO daily (titrate to effect).

  • Furosemide: 40 mg PO daily (often combined with spironolactone).

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Supportive Care

• Abdominal massage and relaxation techniques.

• Probiotics: Some evidence for symptom improvement in IBS-related bloating.

• Counseling and stress management if anxiety contributes to functional bloating.

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Key Notes

• Treatment depends on whether bloating is functional (IBS, dyspepsia) or organic (obstruction, ascites).

• Red flags: rapid progressive distension, severe pain, vomiting, weight loss, or blood in stool → urgent evaluation.

• Symptom-directed drug therapy (simethicone, prokinetics, antispasmodics) is safe but underlying causes must be ruled out.