Endometriosis and IBS are two distinct conditions that often overlap, especially in women of reproductive age. 

Endometriosis involves the growth of endometrial-like tissue outside the uterus, while IBS is a functional gut disorder characterised by symptoms like bloating, abdominal pain, constipation, and/or diarrhoea.

What’s the Connection?

    • High Co-occurrence: Studies suggest that up to 50–80% of women with endometriosis report IBS-like symptoms.
    • Shared Symptoms: Both conditions involve chronic pelvic and abdominal pain, bloating, and bowel changes, making them difficult to distinguish.
    • Visceral Hypersensitivity: Women with both conditions may have heightened sensitivity to gut and pelvic organ signals, amplifying pain perception.
    • Hormonal and Immune Links: Oestrogen and inflammatory pathways are involved in both conditions, suggesting possible shared mechanisms.
    • Diagnostic Delay: The symptom overlap often delays diagnosis of endometriosis or leads to misdiagnosis as IBS alone. 

Impact on Quality of Life

The coexistence of both conditions can significantly worsen pain, fatigue, emotional distress, and day-to-day functioning.

Clinical Implications

  • A diagnosis of IBS does not rule out endometriosis—persistent or cyclical symptoms, especially those worsening around menstruation, warrant further investigation.
  • An integrated management approach—targeting both pelvic and gut symptoms—often yields the best outcomes.

What the science currently shows? 

A recent 2025 study looked at the use of a low FODMAP diet in 47 women with diagnosed endometriosis 

https://bmcwomenshealth.biomedcentral.com/counter/pdf/10.1186/s12905-025-03715-1.pdf

 

 Study Overview

    • Design: Prospective cohort study
    • Participants: 47 women with diagnosed endometriosis and significant bowel symptoms.
    • Intervention: 4-week low-FODMAP elimination phase followed by a ≥10-week reintroduction phase.
    • Assessments: Bowel symptoms and quality of life measured at baseline and post-intervention. 

 

Key Findings

    • Completion Rate: 24 out of 34 participants (71%) who commenced the diet completed the full protocol.
    • Constipation: Significant improvement observed; median score reduced from 7.0 to 5.0 (p = 0.023).
    • Bloating: No statistically significant change; however, 53% of completers reported subjective improvement.
    • Pain Reduction: 65% of completers reported decreased pain, notably in chronic pelvic pain.

 

  • Quality of Life: Significant enhancements in multiple EHP-30 domains:
      • Pain: 47.8 → 29.2 (p = 0.002)
      • Control & Powerlessness: 69.4 → 36.7 (p < 0.001)
      • Emotional Well-being: 45.2 → 29.2 (p = 0.001)
      • Social Support: 46.4 → 31.3 (p = 0.0017)
      • Self-image: 51.2 → 40.5 (p = 0.035)
      • Work-life: 35.0 → 21.7 (p = 0.003)
      • Sexual Intercourse: 61.6 → 45.7 (p = 0.023) 

Study Limitations

  • Sample Size: Small cohort with notable dropout; 13 participants withdrew before starting the diet, primarily due to motivational factors.
  • Study Design: Lack of a control group limits the ability to attribute improvements solely to the diet.
  • Follow-up Duration: Short-term follow-up; long-term effects remain unassessed. ​BioMed Central 

Conclusions

  • The low-FODMAP diet may serve as a promising non-pharmacological intervention for managing bowel symptoms and enhancing quality of life in motivated endometriosis patients.
  • Further large-scale, controlled studies are warranted to confirm these findings and to explore the diet’s efficacy across different endometriosis subtypes and symptom severities. ​

This supports the findings of a previous study by Moore et al. in 2017 

  • Design: Retrospective cohort (n=59)
  • Population: Women with endometriosis and IBS symptoms
  • Outcomes:
    • FODMAP responders: 72% reported global symptom improvement
    • Pain: Marked reduction in bloating, abdominal pain, diarrhoea
    • Pelvic pain improvement: 51% in low FODMAP group vs 25% in standard diet group
  • Conclusion: Low FODMAP diet significantly improved bowel and non-GI symptoms in endometriosis compared to standard diet.

Final thoughts

If you’re experiencing symptoms like bloating, abdominal pain, changes in bowel habits, or pelvic discomfort, it’s understandable to want quick relief. Many people turn to elimination diets—such as low FODMAP or gluten-free approaches—in hopes of managing these issues. But before making any major dietary changes, it’s essential to speak with your GP or healthcare provider first.

Many of the symptoms of Irritable Bowel Syndrome (IBS) and endometriosis overlap, and can also mimic other medical conditions, including inflammatory bowel disease, coeliac disease, or even gynaecological disorders. Without proper assessment, there’s a risk of masking underlying issues or delaying an accurate diagnosis.

Discussing your symptoms with a qualified practitioner ensures that:

  • Any serious or underlying conditions are ruled out or appropriately investigated
  • You receive the right testing and referrals (e.g. breath testing for SIBO, coeliac screening, imaging for endometriosis)
  • A personalised plan is developed that considers your nutritional needs, symptom triggers, and long-term gut health
  • You avoid unnecessary or overly restrictive eating, which can impact nutrient intake, mental health, and microbiome diversity
  • A guided approach—working with a doctor and dietitian—can help you safely explore dietary changes while ensuring your overall health is supported.