Peter Whorwell, Professor of medicine and gastroenterology at Manchester’s Wythenshawe Hospital, and author of “Take Control of Your IBS” (£14.25, Amazon) discusses the link between Endometriosis and Irritable Bowel Syndrome (IBS), and when women should seek further medical guidance if chronic bowel or pelvic pain symptoms go unresolved.
Digestive symptoms such as abdominal bloating, painful cramping, diarrhoea or constipation are often attributed to irritable bowel syndrome (IBS). Yet for some women, these symptoms may be part of a much more complex picture.
Endometriosis can affect the bowel and surrounding pelvic structures, producing gastrointestinal symptoms that closely resemble IBS, making the two conditions difficult to distinguish, and in some cases, they can even occur together.
Research indicates that women with endometriosis are three times more likely to develop IBS compared to those without the condition(1), and gastrointestinal symptoms that resemble IBS are common in people with endometriosis, with some studies reporting them in up to half of patients.
Understanding the relationship between endometriosis and IBS is therefore helpful and identifying when bowel symptoms may be linked to an underlying gynaecological condition can help shorten the path to an accurate diagnosis, open the door to more targeted treatment, and ultimately improve quality of life.
What is Endometriosis?
Endometriosis is a very common condition where pieces of the lining of the womb (the endometrium) can be found outside the womb, either in the ovaries or in other parts of the abdomen.
The only way to definitively diagnose this condition is by passing a camera into the abdomen via the tummy button (umbilicus) and this is called a laparoscopy.
If endometriosis is detected but very mild, it should probably be left alone as treating endometriosis when the pain is due to IBS rather than endometriosis can make the pain worse.
When endometriosis is more severe, then it needs treatment from the gynaecologist. Treatments can include hormonal therapy, surgery and pain management.
What is IBS?
IBS is one of the most common gastrointestinal (GI) disorders seen in primary and secondary care, with one in eight of the adult population suffering from the condition(2, 3, 4). This challenging condition significantly reduces an individual’s quality of life and negatively impacts social functioning and the ability to work, particularly among people with IBS-D and IBS-M, the two sub-types which comprise over 60% of IBS sufferers(5, 6, 7).
More women than men are affected by the condition, but symptoms can usually be managed through a combination of treatments such as adjustments to the diet, laxatives or antidiarrhoeals as appropriate, antispasmodics, enterosorbent gels, neuromodulators and behavioural therapies such as cognitive behavioural therapy and hypnotherapy.
Why are endometriosis and IBS so often confused?
Research suggests the connection between the two conditions are complex.
Endometriosis and IBS don’t just share similar symptoms, they can also affect the body in similar ways, making it difficult to tell them apart.
Inflammation can make the gut more sensitive. Endometriosis causes ongoing inflammation in the pelvis. Over time, this can make the nerves in and around the bowel more sensitive than usual. As a result, normal digestive processes can become painful, leading to symptoms such as bloating, abdominal pain, diarrhoea or constipation that closely resemble IBS.
The brain can struggle to pinpoint where pain is coming from. The pelvic organs and the bowel share many of the same nerve pathways. When endometriosis irritates these nerves, the brain may interpret the pain as coming from the bowel rather than the pelvis. The crossed wires between these nerves means that endometriosis can feel very similar to a bowel disorder, even when the digestive tract itself is healthy.
Because of these shared mechanisms and symptoms, some people with endometriosis are initially diagnosed with IBS, while others may have both conditions at the same time. This is why it’s important to look at the full pattern of symptoms rather than assuming digestive problems are always caused by the bowel alone.
It’s easy to see why confusion can occur and how one condition may be mistaken for the other, leading to a delay in reaching the right diagnosis for each case. If there is any doubt, then it is probably safer to seek treatment for IBS first, and if there is no progress, reconsider the possibility that endometriosis is causing the pain.
So, how can you tell the difference?
As a rule, endometriosis pain is usually linked to the menstrual cycle leading to increased pain experienced around your period, as well as deep pelvic pain during intercourse or bowel movements. Cyclical rectal bleeding is strongly suggestive of endometriosis.
IBS pain is usually colicky and non-cyclical but in some patients the pain can get worse with their periods. Typically, IBS pain gets worse with eating and stress, and the bowel dysfunction is present all the time. IBS pain can occur anywhere in the tummy whereas endometriosis pain is usually below the tummy button.
When to seek further advice
Living with symptoms of IBS and endometriosis can be exhausting and have a significant impact on your quality of life making a more integrated assessment of your condition justified.
If you been diagnosed with IBS but some or all of your symptoms are still unresolved, such as bloating or abdominal pain that may be experienced cyclically in relation to your periods, it should not be ruled out that a gynaecological condition such as endometriosis may be present. Consult your GP to discuss whether a gynaecological referral should be considered as a sensible next step in seeking the best possible management of your symptoms.
If you’ve been diagnosed with endometriosis following a laparoscopy but are still experiencing ongoing symptoms, it may be worth considering whether IBS is also playing a role. This is especially true if your symptoms are not linked to your menstrual cycle or seem more severe than would be expected based on the extent of your endometriosis. Speaking to your GP about the possibility of IBS and asking whether a referral to a gastroenterologist may be appropriate, could help you find more effective symptom relief.
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC9357916/
[2]Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021;70(7):1214-1240.
[3] Lovell RM, Ford AC. Global prevalence of and risk factors for irritable bowel syndrome: a meta-analysis. Clin Gastroenterol Hepatol. 2012;10(7):712-721.
[4] Palsson OS, Whitehead W, Törnblom H, Sperber AD, Simren M. Prevalence of Rome IV Functional Bowel Disorders Among Adults in the United States, Canada, and the United Kingdom. Gastroenterology. 2020;158(5):1262-1273.
[5] S. Ballou and L. Keefer, “The impact of irritable bowel syndrome on daily functioning: characterizing and understanding daily consequences of IBS,” Neurogastroenterology & Motility, vol. 29, no. 4, 2017
[6] P. Singh, K. Staller, K. Barshop et al., “Patients with irritable bowel syndrome-diarrhea have lower disease-specific quality of life than irritable bowel syndrome-constipation,” World Journal of Gastroenterology, vol. 21, no. 26, pp. 8103–8109, 2015.
[7] Sperber AD, Bangdiwala SI, Drossman DA, et al. Worldwide Prevalence and Burden of Functional Gastrointestinal Disorders, Results of Rome Foundation Global Study. Gastroenterology. 2021;160(1):99-114.e3.