Common Causes of Bloating
Bloating is primarily caused by food intolerances, carbohydrate enzyme deficiencies, motility disorders, and visceral hypersensitivity, with specific evaluation and management strategies required for each cause. 1
Primary Causes of Bloating
Food-Related Causes
- Carbohydrate intolerances and enzyme deficiencies:
Functional Gastrointestinal Disorders
- Irritable Bowel Syndrome (IBS) - bloating present in >50% of cases 1
- Functional dyspepsia - bloating and fullness are common symptoms 1
- Functional constipation - retained stool can cause distention 1
- Functional abdominal bloating/distention - Rome IV has a separate diagnostic category for this 1
Motility Disorders
- Gastroparesis - 40% of patients report bloating, correlating with nausea and abdominal fullness 1
- Pelvic floor disorders - dyssynergic defecation can cause constipation and bloating 1
- Small intestinal dysmotility - delays transit and can promote bacterial overgrowth 1
Pathophysiologic Mechanisms
- Small Intestinal Bacterial Overgrowth (SIBO) - excessive fermentation by bacteria 1
- Visceral hypersensitivity - lower sensation thresholds to normal bowel distention 1
- Aerophagia - excessive air swallowing causing gas accumulation 1
- Abdomino-phrenic dyssynergia - abnormal coordination between diaphragm and abdominal muscles 2
Autoimmune and Other Conditions
- Celiac disease - bloating is a common symptom 1, 3
- Non-celiac gluten sensitivity (NCGS) - immune-mediated reaction to gluten or fructans 1, 3
- Inflammatory bowel disease - can present with bloating 3
- Chronic pancreatitis - can cause bloating with pain despite enzyme replacement 1
Evaluation of Bloating
Initial Assessment
- Determine if constipation is present - may indicate IBS-C, chronic constipation, or pelvic floor dyssynergia 1
- Assess for food intolerances - consider 2-week dietary elimination trials for suspected triggers 1, 3
- Screen for alarm symptoms:
- Weight loss >10%
- GI bleeding
- Family history of IBD
- Worsening nausea or pain
- In women >50 years, consider ovarian cancer as bloating can be a presenting symptom 1
Diagnostic Testing
- For suspected celiac disease: Tissue transglutaminase IgA and total IgA levels; small bowel biopsy if serology positive 1, 3
- For suspected SIBO: Consider breath testing in high-risk patients (chronic diarrhea, malnutrition, weight loss) 1, 3
- For severe constipation: Abdominal X-ray may reveal increased stool burden 1
- For upper GI symptoms: Consider upper endoscopy in patients >40 years with dyspeptic symptoms 1
- For suspected motility disorders: Consider gastric scintigraphy or wireless motility capsule for patients with severe nausea/vomiting 1
Common Pitfalls in Diagnosis and Management
- Overlooking food intolerances - these are common and easily treatable causes 1
- Missing psychological components - anxiety and stress can significantly contribute to symptoms 2
- Overtreatment with antibiotics - prolonged use for presumed SIBO without confirmation should be avoided 3
- Misdiagnosis - postprandial symptoms can be mistaken for more serious conditions 3
- Inadequate dietary management - can lead to nutritional deficiencies 3
- Failure to recognize abdomino-phrenic dyssynergia - a treatable cause of visible distention 2
By understanding these diverse causes of bloating, clinicians can develop targeted diagnostic and treatment strategies that address the underlying pathophysiology rather than just treating symptoms.