IBS Does Not Cause Acne or GERD
IBS does not cause acne or GERD; however, these conditions frequently overlap due to shared pathophysiological mechanisms, particularly visceral hypersensitivity and gut-brain axis dysfunction. 1, 2
The Relationship Between IBS and GERD
Evidence of Overlap, Not Causation
Up to 79% of IBS patients report GERD symptoms, and up to 71% of GERD patients report IBS symptoms, but this represents overlap rather than one condition causing the other. 2
Among IBS patients, 63.6% also have GERD (OR = 3.2,95% CI: 2.9-3.7), and among GERD patients, 33.9% meet Rome criteria for IBS (OR = 3.6,95% CI: 3.1-4.3). 3
A study of 1,489 IBS patients found that 97% had erosive esophagitis on endoscopy, though only 66% reported GERD symptoms. 4
Shared Pathophysiology
Both IBS and GERD are disorders of gut-brain interaction with shared mechanisms including visceral hypersensitivity and altered gut reactivity, which explains their frequent co-occurrence. 1, 5
The overlap could be explained by either GERD affecting different levels of the GI tract or a high overlap rate due to similar underlying GI dysfunction affecting smooth muscle or sensory afferents. 2, 6
Clinical Implications
Patients with both IBS and GERD have significantly lower quality of life than those with either condition alone and perceive their symptoms as more severe. 1, 6
These patients are less likely to respond to anti-reflux treatment compared to those with GERD alone. 6
Prevalence of all functional GI symptoms is higher in patients with overlapping GERD and IBS, suggesting a common underlying dysfunction rather than causation. 3
The Relationship Between IBS and Acne
Evidence of Association, Not Causation
A 2021 prospective controlled study found that 61% of acne vulgaris patients had IBS compared to 28% of healthy controls (P = .001), representing the first study to examine this relationship. 7
There was a statistically significant relationship between acne severity (GAGS scores) and IBS diagnosis (P = .001), as well as specific IBS symptoms including abnormal stool form, abdominal distention, and incomplete evacuation. 7
Proposed Mechanisms
The association likely reflects shared pathophysiological mechanisms rather than direct causation, potentially involving gut-brain axis dysfunction, inflammation, or microbiome alterations that affect both the GI tract and skin. 7, 5
The gut microbiome can modify intestinal permeability, visceral sensitivity, and host immune responses, which may have systemic effects including skin manifestations. 5
Clinical Approach
Diagnostic Considerations
Recognize that 42-87% of IBS patients also have functional dyspepsia, which includes upper GI symptoms like nausea and epigastric pain that may be confused with GERD. 8, 5
When evaluating patients with multiple functional GI symptoms, consider them as overlapping disorders of gut-brain interaction rather than one causing the other. 5, 1
Important Pitfalls
Do not overlook alarm features (age >50 at onset, rectal bleeding, unintentional weight loss, nocturnal symptoms, fever) that warrant investigation beyond functional diagnoses. 1, 8
The British Society of Gastroenterology emphasizes that IBS is not associated with increased risk of cancer or mortality, but significantly affects quality of life. 5
When both conditions are present, treat each condition on its own merit using evidence-based therapies, as the overall approach to overlapping functional disorders should be similar. 5, 8