Is it IBS or endometriosis?

Did you know that IBS and endometriosis share a range of common symptoms that can result in misdiagnosis?

Overlapping symptoms between endometriosis and IBS

Endometriosis and IBS share multiple common symptoms. The table below highlights which symptoms do and don’t overlap:

In fact, IBS and endometriosis often coexist. For instance, a meta-analysis found that 23% of women with endometriosis had IBS{Nabi, 2022 #2721}, while another found that ~⅓ of women with endometriosis met the Rome criteria for IBS{Ek, 2021 #5553}.

Although fewer studies have examined the risk of endometriosis in women with IBS, the reverse also appears to be true. For example a retrospective study of 160 women with IBS found that 37% had co-existing endometriosis{Moore, 2017 #916}, another reported that 41% of patients with IBS had coexisting endometriosis{Droz, 2011 #3162} and a meta-analysis found that women with IBS have a 3-fold risk of an endometriosis diagnosis{Nabi, 2022 #2721}.

These overlapping symptoms and high rates of coexisting endometriosis and IBS make distinguishing between the two conditions difficult and raise the possibility of misdiagnosis. For instance one study found that almost 80% of women with IBS actually had endometriosis on laparoscopy{Seaman, 2008 #933}, while another found that 21% of patients undergoing laparoscopy for suspected endometriosis had previously been diagnosed with IBS, and of these, 79% went on to have endometriosis confirmed on laparoscopy{Maroun, 2009 #932}.

So what does all this mean for women with IBS?

Being aware of the red flags that might indicate underlying endometriosis is important. These include:

• period pain (also known as dysmenorrhoea)
• pain when using your bladder or bowels (usually during your period)
• pain during or after sex (dyspareunia )
• ovulation pain (during the middle of the menstrual cycle). This can include pain in the legs, buttocks, and thighs
• Fatigue
• Infertility
• Other symptoms (pelvic pain not related to a period, heavy/prolonged/irregular bleeding and GI symptoms such as nausea, bloating, painful defecation, diarrhoea or constipation)

If you’ve been diagnosed with IBS and the symptoms above resonate with you, book in to talk to your GP.

The Raising Awareness Tool for Endometriosis (RATE)

The Raising Awareness Tool for Endometriosis (RATE) is a quick, online quiz you can use to assess your symptoms and create a report that can be downloaded and discussed with your doctor. It was developed by a team of experts at the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) - the training college for specialists who treat endometriosis.

A recent review article titled ‘When to suspect endometriosis in IBS: tips for the gastroenterologist’ aimed to highlight the co-existence of endometriosis and IBS, and provide practical tips on screening for endometriosis and helping patients on seeking a diagnosis. The paper recommended a series of questions to screen patients presenting to a gastroenterologist for possible underlying endometriosis. These questions included:

• Do you miss school or work because of period pain?
• Do you experience pelvic pain throughout the month?
• Is opening your bowels painful during your period?
• Do you experience pain during or after sex?
• Does anyone in your family have endometriosis?
• Have you been prescribed the contraceptive pill to treat painful periods?
• Have you had difficulty becoming pregnant in the past?

The paper recommends that patients answering yes to more than 1 of these questions be referred back to their GP for further investigation, initial management and/or referral on to a gynaecologist.

So where to from here?

If you have diagnosed or suspected IBS, but have some endometriosis red flags above, it might be time to discuss your concerns with your GP or gastroenterologist, and to ask for a referral to a gynaecologist.

Keeping a record of your symptoms and menstrual cycle can help to guide this discussion. You can use period tracking apps or just a paper diary to do this, marking the first day of your period as day 1 in your cycle. Completing the RATE questionnaire and taking the downloadable report to your appointment can also help.

We know that diagnostic delay for endometriosis is long in Australia and experiencing years of pain without answers and continuing to advocate for yourself can feel exhausting, but getting a diagnosis is important to validate your symptoms, begin treatment, reduce symptoms and improve quality of life.

References

Filewood, R., Tibbot, J., Hardy, D. (2025). When to suspect endometriosis in IBS: tips for the gastroenterologist. Frontline Gastroenterology, 0(1-7). https://doi.org/10.1136/flgastro-2025-103086

Galica, A., Galica, R., Dumitrascu, D. (2025). Intestinal Endometriosis, A Challenge for Gastroenterologists: A Narrative Review. J Gastrointestin Liver Dis. 34(3): 381-389. https://doi.org/10.15403/jgld-6456