There is a particular kind of frustration that comes with endometriosis.
You can spend years trying to understand your pelvic pain, your periods, your fatigue and everything else that comes with it.
And then there is your stomach.
The bloating.
The constipation.
The diarrhoea.
The feeling that you look several months pregnant by the end of the day.
The abdominal pain that seems to appear from nowhere.
And perhaps the most frustrating part is not knowing what belongs to what.
Is this my endometriosis?
Is it IBS?
Is it something I have eaten?
Or have I somehow reached the point where I am supposed to remove half the contents of my kitchen just to get through the week?
It is a question I am asked increasingly often.
And the honest answer is that the relationship between endometriosis, the bowel and food is complicated.
But there is some genuinely interesting research emerging, particularly around women who have endometriosis alongside IBS-type gastrointestinal symptoms.
So, rather than giving you another list of foods you apparently must never eat again, let’s look at what we actually know.
First things first: endometriosis and IBS can coexist
Endometriosis and irritable bowel syndrome are different conditions.
That sounds obvious, but the symptoms can overlap considerably.
Endometriosis can cause pelvic and abdominal pain, painful bowel movements and gastrointestinal symptoms, particularly around menstruation.
IBS can cause abdominal pain, bloating, constipation, diarrhoea or changes in bowel habit.
And, unfortunately, it is entirely possible to have both.
In fact, the association appears to be quite strong.
A 2022 systematic review and meta-analysis found that people with endometriosis had almost three times the odds of having IBS compared with people without endometriosis. Across the studies that looked specifically at prevalence, around 23% of people with endometriosis also had IBS.
That does not mean that endometriosis causes IBS.
It also doesn’t mean that every episode of bloating or constipation in somebody with endometriosis is IBS.
It does mean that if you have endometriosis and significant gastrointestinal symptoms, it is worth considering that there may be more than one thing going on.
And that distinction becomes important when we start talking about diet.
So, what exactly is a FODMAP?
FODMAP is one of those words that sounds considerably more complicated than it needs to be.
It stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols.
These are types of short-chain carbohydrates found in a wide variety of foods.
For some people, particularly those with IBS, certain FODMAPs are poorly absorbed in the small intestine and can draw water into the bowel and be fermented by gut bacteria.
The result can be bloating, abdominal discomfort, wind, diarrhoea or other gastrointestinal symptoms.
And this is where the low-FODMAP diet comes in.
The important word is low.
It is not supposed to mean no FODMAPs forever.
A proper low-FODMAP approach is generally a short-term process involving an initial period of reducing high-FODMAP foods, followed by systematic reintroduction and personalisation.
The aim is not to end up with the smallest possible diet.
It is to work out what your individual gut actually tolerates.
That distinction matters enormously.
But does low-FODMAP actually help endometriosis?
This is where things have become particularly interesting.
For years, there has been a lot of discussion about diet and endometriosis, but relatively little high-quality evidence behind many of the claims made online.
There is certainly no single diet that has been shown to cure endometriosis.
However, researchers have started looking more specifically at women with endometriosis who also have significant gastrointestinal symptoms.
And the results are beginning to suggest that low-FODMAP may help some of these women.
A particularly interesting study published in 2025 was the EndoFOD trial.
It was a randomised controlled crossover study involving 35 women with endometriosis and poorly controlled gastrointestinal symptoms.
Participants followed either a low-FODMAP diet or a nutritionally matched control diet for 28 days before crossing over to the other diet.
After four weeks, 60% responded to the low-FODMAP diet compared with 26% during the control diet.
There were also improvements in abdominal pain, bloating, stool consistency and quality of life.
That is interesting.
But it needs interpreting carefully.
It was a relatively small study.
It lasted four weeks.
And it looked specifically at women with endometriosis who already had significant gastrointestinal symptoms.
It does not show that a low-FODMAP diet treats the underlying endometriosis.
What it does suggest is that reducing FODMAPs may be a useful way of managing gastrointestinal symptoms in some women with endometriosis.
And that is a much more sensible conclusion.
Think symptoms, not cure
This is probably the most important distinction I would make.
If somebody with endometriosis tells me that changing their diet has made their bloating, bowel symptoms or abdominal discomfort considerably better, I absolutely believe that experience.
But symptom improvement does not necessarily mean that the endometriosis itself has disappeared or become less extensive.
You can improve a symptom without treating the underlying disease.
We do this in medicine all the time.
Painkillers can reduce pain without removing its cause.
Treating constipation can improve abdominal discomfort without changing the underlying condition.
And, in the same way, dietary intervention may improve gastrointestinal symptoms without treating endometriosis itself.
That doesn’t make the improvement unimportant.
Quite the opposite.
If your bowel symptoms are affecting your work, sleep, relationships, social life or simply your ability to wear trousers comfortably by 4pm, improving them matters.
This is where IBS becomes particularly relevant
The overlap between endometriosis and IBS is one reason I think the low-FODMAP conversation needs to be handled carefully.
If you have endometriosis and IBS, a low-FODMAP diet may be addressing the IBS component of your symptoms rather than the endometriosis itself.
And that could still make a very significant difference to how you feel.
It is also one reason why I would be cautious about assuming that every bowel symptom in someone with endometriosis is simply “part of the endometriosis”.
Persistent or troublesome bowel symptoms deserve proper assessment.
Sometimes there is endometriosis affecting the bowel.
Sometimes there is IBS.
Sometimes there is constipation.
Sometimes there is more than one thing happening at once.
And sometimes the answer is not related to endometriosis at all.
Good medicine starts with working out which problem we are actually trying to solve.
Don’t assume every bowel symptom is IBS
There is one important point I would add here.
If you have endometriosis, it can be very tempting to put every new abdominal or bowel symptom down to the endometriosis itself, or to IBS if you have already been given that diagnosis.
But a new or persistent change in your bowel habits should not simply be written off as part of your endometriosis or managed through diet without speaking to a doctor.
That might mean a change in how often you open your bowels, persistent diarrhoea or constipation, a change in the consistency of your stools, or symptoms that are noticeably different from your usual pattern.
You should also seek medical advice if you notice blood in your stool, unexplained weight loss, persistent abdominal pain or bloating, or other symptoms that are unusual for you.
These symptoms are very often caused by conditions other than bowel cancer, and having them does not mean that something serious is wrong. But they are symptoms that deserve proper assessment rather than simply being attributed to IBS or endometriosis.
This is particularly important if symptoms are new, persistent or changing.
Diet can be part of symptom management. It shouldn’t become a substitute for finding out what is causing the symptoms in the first place.
And that is an important distinction throughout this whole conversation.
And no, you don’t need to stop eating everything
This is the part I worry about most when I see social media discussions about endometriosis and diet.
There are an enormous number of lists telling women to avoid gluten.
Or dairy.
Or sugar.
Or meat.
Or soya.
Or nightshade vegetables.
Or processed foods.
Or carbohydrates.
Or practically anything enjoyable.
Some of these approaches may make an individual person feel better.
But that is not the same as having good evidence that they should be recommended to everybody with endometriosis.
Endometriosis UK is very clear that there is currently limited high-quality evidence for a specific diet for endometriosis. Their guidance on low-FODMAP specifically distinguishes between using it for IBS or IBS-type gastrointestinal symptoms and treating endometriosis itself.
And this matters because restrictive diets are not completely harmless.
They can make eating socially difficult.
They can make meals unnecessarily complicated.
They can increase anxiety around food.
And if enough foods are removed, there is a genuine risk of nutritional inadequacy.
The aim should not be to see how little you can eat.
It should be to work out what helps you feel better while keeping your diet as varied and nutritionally adequate as possible.
Low-FODMAP isn’t supposed to be forever
This is perhaps the biggest misconception about the diet.
The elimination phase is not meant to become your permanent diet.
The whole point is to identify which foods or groups of foods are actually contributing to your symptoms and then gradually reintroduce foods to establish your own level of tolerance.
That is why professional guidance is important.
NICE recommends that formal dietary exclusion and reintroduction approaches for IBS, including low-FODMAP diets, should be supported by a healthcare professional with expertise in dietary management.
Endometriosis UK also recommends working with a registered dietitian if you are considering a low-FODMAP approach.
In other words, this shouldn’t be a case of downloading a food list from Instagram on Monday and deciding that onions, apples, bread and milk are permanently banned by Friday.
There is a process.
And there is a reason for that process.
What about all the other “endometriosis diets”?
This is where I think a healthy dose of scepticism is useful.
There are diets described online as anti-inflammatory, endometriosis-specific, hormone-balancing, autoimmune, gluten-free, dairy-free and many other variations.
Some are based around generally healthy principles.
Others are extremely restrictive.
But at the moment, there isn’t good-quality evidence to support one particular diet as a treatment for endometriosis itself.
That doesn’t mean nutrition is irrelevant.
Far from it.
Eating a varied diet, getting enough fibre and protein, staying hydrated and maintaining good general nutrition are all important for health.
But there is a big difference between:
“A healthy diet is good for you.”
and
“This particular diet will treat your endometriosis.”
The first is sensible.
The second needs evidence.
And unfortunately, there is a lot more certainty about the second claim on social media than there is in the scientific literature.
What I would actually suggest
If you have endometriosis and significant gastrointestinal symptoms, I wouldn’t start by trying to eliminate everything.
I’d start by asking a few questions.
What symptoms are you actually trying to improve?
When do they occur?
Are they linked to your menstrual cycle?
Are you constipated, having diarrhoea, or alternating between the two?
Is bloating your main problem?
Have you been diagnosed with IBS as well as endometriosis?
Are there symptoms that need investigating rather than simply managing through diet?
And what is your diet currently like?
Sometimes a few straightforward changes can make a difference.
Sometimes IBS is part of the picture and a structured low-FODMAP approach may be worth considering.
And sometimes the most useful thing you can do is stop trying to solve everything with food.
Because not every symptom is caused by something you ate.
The bigger picture
One of the things I find particularly interesting about endometriosis is that it rarely behaves like a single-organ problem.
Pain, bowel symptoms, bladder symptoms, fertility, fatigue and quality of life can all become part of the picture.
That means treatment often needs to be broader than simply asking, “What can we do about the endometriosis?”
Sometimes the question is also:
“What else is contributing to how this woman feels?”
For some women, that may include IBS.
For some, constipation.
For some, pelvic-floor dysfunction.
For some, other gastrointestinal conditions.
And for some, diet may genuinely be one part of managing their symptoms.
That is very different from saying that food is the cause of endometriosis.
Or that removing the right food will cure it.
So, can changing your diet help?
Possibly.
And increasingly, we have evidence that for women with endometriosis and significant gastrointestinal symptoms, a carefully managed low-FODMAP approach can improve some of those symptoms.
The 2025 EndoFOD trial is interesting because it gives us more evidence than we had previously. But as I mentioned it is still a small study, and we need more research, particularly looking at longer-term outcomes and what happens after foods are reintroduced.
So I think the sensible position is somewhere between the two extremes.
You don’t need to believe that diet has nothing to do with your symptoms.
And you don’t need to believe that there is a secret “endometriosis diet” that somebody on Instagram has discovered and your doctor hasn’t told you about.
There is a middle ground.
Understand your symptoms.
Work out whether IBS or another gastrointestinal problem might also be present.
If appropriate, consider dietary intervention with someone properly trained to deliver it.
And, most importantly, don’t let managing endometriosis turn eating into another source of stress.
Food should still be food.
Not another thing to be frightened of.
And if changing what you eat makes your bowel symptoms better, that is useful information.
It is just not the same thing as saying that you have treated the endometriosis.
That distinction matters.
Because good healthcare isn’t about finding one perfect answer.
It is about understanding the whole picture and working out what might actually help you feel better.
If you are experiencing pelvic pain, bowel symptoms, painful periods or other symptoms that you think may be related to endometriosis, a proper clinical assessment can help work out what may be contributing to your symptoms and whether further investigation is appropriate.
Dietary management is individual, and a low-FODMAP diet should be undertaken with guidance from a registered dietitian. If you develop new or persistent changes in your bowel habit, it is important to have these assessed by a Doctor.