IBS or something else? Conditions with the same symptoms

You can’t tell from symptoms alone, and neither can a website or a quiz. Coeliac disease, inflammatory bowel disease, bowel cancer, ovarian cancer, endometriosis, lactose intolerance and diverticular disease all overlap with IBS. That overlap is the reason a GP is meant to check for other causes before calling it IBS.

So read this page as a list of reasons to go back to your GP, not a list of things to rule in or out yourself. The NHS stomach ache page puts it plainly: “Do not self-diagnose.”

Why do so many conditions look like IBS?

Because the gut has a small vocabulary. Pain, bloating, diarrhoea, constipation and tiredness can come from irritation, inflammation, an immune reaction, a growth, or a gut that’s oversensitive to its own movements, and from the outside they can feel the same.

That’s why IBS is meant to be a positive diagnosis, made when there are no red flag symptoms and tests find no other cause. The Crohn’s page on the NHS website lists IBS, ulcerative colitis, diverticular disease and coeliac disease as conditions with similar symptoms, and the endometriosis page names IBS among its lookalikes too. If you’d like to see what those tests are, how IBS is diagnosed in the UK walks through them.

Which conditions share symptoms with IBS?

Here they are, with what the NHS lists for each. The middle column is the overlap. The right hand column is what is worth telling your GP about, because it changes what they look for.

None of these rows is a scoring system. Having something from the right hand column doesn’t mean you have that condition, and having nothing from it doesn’t mean you don’t. The symptoms of ovarian cancer, for instance, are common and can be caused by many different conditions. That is exactly why they need checking by someone who can examine you and order tests.

How are these checked?

Mostly through the same few steps, which is reassuring when you’re dreading a long run of hospital visits. A GP asks about your symptoms and family history, may examine your tummy, and often starts with blood tests and a poo sample. A coeliac antibody blood test, inflammation markers and, depending on your symptoms, a home poo test for bleeding or a blood test for a protein called CA125 that’s sometimes linked to ovarian cancer, are all things a GP can arrange.

From there, a GP refers you to a hospital specialist when the tests or symptoms call for it, for scans, a camera test or a biopsy. A referral is a step in finding out. It doesn’t mean the answer is the worst one.

What should I avoid while I wait?

Changing your diet before the tests. Coeliac testing needs gluten in your diet when the blood test is done, because avoiding it could lead to an inaccurate result, and you shouldn’t start a gluten free diet until a specialist confirms the diagnosis. More broadly, don’t cut foods out without the advice of a GP or dietitian, and don’t rely on bought intolerance tests, which I’ve covered in do food intolerance tests work.

When should I go back to my GP?

Any of these is a good reason, even if you’ve already been told it’s IBS:

• your symptoms have changed, or something new has started
• you have symptoms of ovarian cancer and “you have previously seen a GP, but your symptoms have not gone away, are worse or more frequent”
• you’ve never been tested for coeliac disease
• you have a family history of bowel disease such as cancer, colitis or Crohn’s disease, or of coeliac disease, or of ovarian or breast cancer, and you haven’t mentioned it
• bloating has become constant, which I’ve written about in bloating that will not go away

Which symptoms should not wait?

These are in the NHS’s own words, and they go to a GP, NHS 111 or 999, not to a search engine.

Ask for an urgent GP appointment or get help from NHS 111 if:

• “you have lost a lot of weight for no reason”
• “you’re bleeding from your bottom or have bloody diarrhoea”
• “you find a hard lump or swelling in your tummy”
• “you have shortness of breath, noticeable heartbeats (palpitations) and skin that’s paler than usual”
• “your poo is black or dark red”

Call 999 or go to A&E if:

• “a stomach ache came on very suddenly or is severe”
• “you’re vomiting blood or your vomit looks like ground coffee”
• “you’re bleeding non-stop from your bottom”
• “there’s a lot of blood or you see large blood clots when you poo”
• “you cannot poo or fart”

If bloating is your main worry and you want help deciding what to do next, the bloating quiz won’t tell you what’s causing it. It will tell you where to take it.