Chronic Bloating: Lab Tests That Can Help Find the Cause

Chronic bloating affects quality of life and can signal underlying issues. While some causes require specialized testing, blood tests can reveal important clues.

Common Causes of Bloating

• Celiac disease
• Food intolerances
• SIBO (small intestinal bacterial overgrowth)
• Thyroid dysfunction
• Hormonal imbalances
• Digestive enzyme deficiency

Helpful Lab Tests

Celiac Screening

• Tissue transglutaminase (tTG) IgA
• Total IgA (to ensure valid results)
• Deamidated gliadin peptide (DGP) if IgA deficient

Thyroid Panel

Hypothyroidism slows digestion and causes bloating, constipation, and fluid retention.

Inflammatory Markers

• CRP
• ESR
• Fecal calprotectin (stool test)

Other Considerations

• Complete metabolic panel (liver and kidney function)
• CBC (anemia from malabsorption)
• Vitamin and mineral levels (B12, iron, vitamin D - low levels may indicate malabsorption)

Beyond Blood Tests

Some bloating causes require:

• Breath tests (SIBO, lactose intolerance)
• Stool testing
• Endoscopy/colonoscopy
• Food elimination trials

Blood tests help rule out or identify certain causes, narrowing down the investigation.

References

• Rubio-Tapia, A., et al. (2013). ACG clinical guidelines: diagnosis and management of celiac disease. American Journal of Gastroenterology, 108(5), 656-676.
• Lacy, B. E., et al. (2021). Management of chronic abdominal distension and bloating. Gastroenterology, 160(3), 1019-1040.