Can Constipation Cause Heartburn?
Constipation itself does not directly cause heartburn or GERD, but there is significant overlap between gastrointestinal symptoms in patients with functional disorders, and both conditions may coexist due to shared underlying gastrointestinal dysfunction rather than a direct causal relationship. 1, 2
Understanding the Symptom Overlap
The evidence shows substantial overlap between upper and lower gastrointestinal symptoms, but this represents co-occurrence rather than causation:
- Up to 79% of patients with irritable bowel syndrome (IBS), which commonly includes constipation, report GERD symptoms, while up to 71% of GERD patients report IBS symptoms 2
- Approximately 66% of patients with GERD and heartburn also experience epigastric pain simultaneously, demonstrating how gastrointestinal symptoms frequently cluster together 3, 4
- Patients with functional heartburn have higher rates of overlapping functional dyspepsia (62%) and IBS symptoms (48%) compared to those with typical GERD 5
Why These Conditions Co-Occur
Two principal theories explain the common presence of both upper and lower GI symptoms:
- Shared gastrointestinal dysfunction: Both conditions may result from generalized disorders of smooth muscle function or sensory nerve abnormalities affecting the entire GI tract 2, 6
- Common underlying pathophysiology: Genetic studies and similarities in gastrointestinal sensory-motor abnormalities suggest a systemic GI disorder rather than isolated organ dysfunction 2
Clinical Implications for Management
When evaluating patients with both constipation and heartburn:
- Address constipation as a primary concern in patients with 22q11.2 deletion syndrome or those taking medications like clozapine, as constipation is a recognized gastrointestinal issue requiring dietary interventions and prophylactic laxatives 1
- Initiate PPI therapy (omeprazole 20 mg once daily before meals) for heartburn symptoms, as over 80% of patients with heartburn as the predominant symptom have GERD 4
- Consider that anxiety, thyroid disease, and other comorbid conditions may contribute to both constipation and GI symptoms 1
Important Caveats
- Never dismiss cardiac causes in patients presenting with epigastric discomfort or heartburn-like symptoms—obtain an ECG within 10 minutes and measure cardiac troponins at 0 and 6 hours, as myocardial infarction can present atypically with epigastric pain 3, 4
- Recognize that symptom improvement with anti-reflux treatment does not prove causation—some studies show IBS-like symptoms improve with PPI therapy, but this may reflect the gastrocolic reflex rather than direct causation 7
- Patients with functional heartburn are more likely to have anxiety and depression (92% and 88% respectively), which can contribute to both upper and lower GI symptoms 5