Women with IBS and endometriosis are three times more likely to respond to a low FODMAP diet than women with IBS alone, Australian researchers report.

Writing in the paper published in the Australian and New Zealand Journal of Obstetrics and Gynaecology the authors led by Judith Moore from The Alfred Hospital in Melbourne said the findings suggested the presence of endometriosis: “May be a clinical predictor of a higher likelihood of response to the low FODMAP diet, presumably because of the causal association with visceral hypersensitivity”.

The retrospective study involved 160 women attending a private specialist IBS service in Christchurch, New Zealand. Almost two-fifths of the cohort (n=59) had co-existing IBS and endometriosis.

After following a low FODMAP diet for four weeks 72 percent of the women with both conditions reported a more than 50 percent improvement in their bowel symptoms.

This compared to 49 percent of the women with no known endometriosis. (P=0.001, OR 3.11, 95% CI 1.5-6.2).

The researchers found that women with diagnosed endometriosis in the study were more likely to report pain during sexual intercourse, menstruation that affected bowel symptoms and pelvic pain.

As endometriosis was notoriously challenging to diagnose the authors suggested the symptoms should be treated as ‘red flags’, particularly if they are reported in conjunction with a family history of endometriosis.

“[these] clinical features should promote further investigation and consideration of endometriosis with the hope that the diagnosis is missed in fewer patients in the future,” they wrote.

FODMAPs are fermentable oligosaccharides disaccharides, monosaccharides and polyols, a groups of short chain carbohydrates found in fruits, vegetables and grains.