IBS, colitis or Crohn’s? When to see a doctor about your stomach ache

Tummy ache
Common symptoms such as diarrhoea or constipation could be due to infection, medication or a change in diet - Getty

Standing in a muddy field at Glastonbury, Tom Dawson realised something wasn’t right. Although bowel disease wasn’t top of his mind as he watched his favourite bands, he couldn’t dismiss the urgent need to poo. In fact, he realised it was impossible to make it through a whole set without having to trudge through the mud to a bank of portaloos before it was too late.

“It was obvious this wasn’t normal,” he says. “No one else was rushing off to the toilet like I was.” Back from the festival, he finally went to the GP, and was referred to a specialist for further tests. What he had initially dismissed as just needing the loo more often turned out to be ulcerative colitis.

Knowing when to seek help

Like so many people with bowel conditions, Tom put off seeking medical help, not realising quite how severe his symptoms had become. Embarrassment, hope that symptoms will pass and fear of cancer are other common reasons that people delay initial contact with their GP.

But Professor Miles Parkes, a gastroenterologist in Cambridge, urges people to seek help early. “Delaying diagnosis leads to worse outcomes, so people should get things checked out,” he says.

A big challenge when it comes to bowel disease is that common symptoms such as diarrhoea or constipation could be due to infection, medication or a change in diet – or they could signal something more serious.

Google your symptoms and you might land on bowel cancer, but it could also be Crohn’s disease, ulcerative colitis, irritable bowel syndrome (IBS), coeliac or diverticulitis. With such common and overlapping symptoms, getting to the bottom of the issue can take a bit of medical detective work.

Through a combination of blood tests, stool tests or taking a look inside the gut with an endoscopy or colonoscopy, doctors can identify what’s going on.

Your gut is basically a long tube of muscle that begins at your mouth and ends at your bottom. If the movement of food and waste through your digestive system is affected, you may feel bloated, have abdominal pain and experience diarrhoea or constipation.

If these symptoms persist with no obvious explanation, it’s time to get checked out.

Irritable bowel syndrome

“IBS is far and away the most common condition,” says Prof Parkes. Estimates suggest that 5-20 per cent of the population may have IBS, though many people have not sought an official diagnosis and have learnt to self-manage the condition.

Managing your symptoms

“Lifestyle is an important part of management of IBS,” he says. “Stress can make your symptoms worse, so it is important to make time for stress-relieving activities, such as exercise.

“Dietary intolerances are relatively common with IBS” he says. “Quite often it’s the healthier foods that make the symptoms worse – particularly pulses and brassica vegetables, but it can be quite individual.”

IBS is still quite poorly understood, but a large UK Biobank study showed that at a genetic level, IBS and anxiety are closely linked. “It’s not that anxiety is causing IBS symptoms,” explains Prof Parkes, “but IBS and anxiety may have a sort of common origin”.

Getting a diagnosis

Bowel conditions are classed as either ‘functional’ or ‘pathological’ explains Dale Vimalachandran, a consultant colorectal surgeon from Chester and Liverpool. Irritable bowel syndrome (IBS) is a functional condition because it affects the way the bowel works, but without visible signs of damage or inflammation of the bowel lining.

In other conditions such as Crohn’s, ulcerative colitis, coeliac and diverticulitis, there are physical signs of the disease that can be seen in scans, or under the microscope.

Crohn’s and ulcerative colitis

Crohn’s and ulcerative colitis are the main inflammatory bowel diseases (IBD). “People get really confused between IBD (inflammatory bowel disease), and IBS, which is irritable bowel syndrome. But they are two completely separate things,” says Prof Parkes.

Crohn’s and ulcerative colitis are life-long autoimmune diseases where the immune system starts to attack parts of the gut, causing inflammation or ulcers. In Crohn’s this can occur at any point in the gut from mouth to anus, while ulcerative colitis affects only the colon.

Managing your symptoms

Steroids can be used to treat flare-ups of IBD by suppressing the immune system, allowing the gut to heal, but they are only suitable for short-term use due to their side-effects. New medicines called ‘biologics’ have been developed and these are used in patients with more advanced disease to reduce the risk of needing surgery.

Professor Parkes was chief investigator on a recently published study called PROFILE, which showed that giving Crohn’s patients a biologic called infliximab at diagnosis, rather than waiting for their condition to get more advanced. This meant they were ten times less likely to need surgery later on.

This finding could make a huge difference to people newly diagnosed with Crohn’s and the team is working to get the approach incorporated in updated Nice guidelines to ensure patients can access it.

Getting a diagnosis

Crohn’s disease tends to be diagnosed at 15-40 years of age, while most diagnoses of ulcerative colitis come at 15-25. “I felt really sad when I was diagnosed with ulcerative colitis” says 24-year-old Georgia O’Connor. “I didn’t understand how I could live such a healthy lifestyle and get sick like that”.

“I was going to the toilet around 15-20 times a day, sometimes even more,” she says. “One day I counted 47 times.”

“As a professional boxer it was incredibly difficult. I felt tired all the time, my joints would ache, I had absolutely no energy,” O’Connor explains. “I was so anxious about having an accident in the gym or during a fight”.

Although frustrated at the diagnosis, O’Connor was relieved to finally have some answers, and get help she needed. “Having the right medication has helped me to carry on doing what I love” she says.

“The aim for us as gastroenterologists is to restore people to normal life, to normal health, so they can do normal activities,” says Prof Parkes. “Of course, there’s always going to be a small proportion of people for whom that’s not possible, but for the vast majority of people with Crohn’s disease and ulcerative colitis, that is absolutely the case.”

Coeliac disease

Another autoimmune disease is coeliac, which affects around one in 100 people. Unlike Crohn’s and ulcerative colitis, it is the presence of gluten that triggers the immune system to attack healthy tissue in the gut. The resulting inflammation can prevent proper absorption of nutrients, leading to tiredness and anaemia, as well as severe abdominal pain and diarrhoea.

Managing your symptoms

Coeliac symptoms can occur at any point in life, but the majority of people get diagnosed between 40 and 60 years of age. This could be due to delays in confirming a diagnosis of coeliac (sometimes mistaken for IBS) or due to the late onset of symptoms.

Maintaining a completely gluten-free diet can be difficult and making gluten-free meals on a budget is a particular challenge due to limited choice of products. Coeliac UK is campaigning for affordable gluten-free options, and has a range of gluten-free recipes to help you beat the cost-of-living crisis and stay healthy.

Getting a diagnosis

It should be noted that Coeliac is very different to gluten intolerance. Although people with gluten intolerance may experience similar symptoms when there is gluten in their diet, the presence of gluten does not cause damage to the lining of the gut, and unlike coeliac, intolerances may be temporary.

There is no cure for coeliac except adopting an entirely gluten-free diet. Even a tiny amount of gluten could cause lasting damage to the gut and increase the risk of complications, so even asymptomatic patients are advised to go gluten-free to reduce the risk of gut damage or associated conditions such as diabetes.


A lesser-known bowel issue is diverticulitis. As we age, the vast majority of us will develop small pouches in the bowel, called diverticula. The older you are, the more likely it is that you will have them.

Managing your symptoms

The presence of diverticula isn’t necessarily a problem in itself, but in about 10-20 per cent of people they become blocked or infected, causing abdominal pain, discomfort and a change in bowel habits. In the worst case, this can lead to the need for emergency surgery to drain an abscess or treat perforation of the bowel. Once again, seeking help early reduces the risk of complications, and you may be given antibiotics to clear up the infection before it can do further damage.

Getting a diagnosis

“It’s time to normalise conversations about poo,” says Ruth Wakeman, the director of services, advocacy and evidence at Crohn’s & Colitis UK. “We know symptoms like blood in your poo, frequent diarrhoea and stomach pain can be tempting to ignore, but if you have any of them, you need to see a doctor,” she says.

The charity’s ‘Cut the Crap’ campaign challenges people to stop making excuses and see the doctor. “There’s nothing to be embarrassed about,” O’Connor reminds us. “We are all human beings, and our bodies work in weird and wonderful ways”.

Helpful resources

Crohn’s & Colitis UK’s symptom checker is a quick online questionnaire that asks about common symptoms. It also creates a letter to take to your doctor which is helpful if you find it hard discussing symptoms. See Coeliac UK; Bowel Research UK and Bowel Cancer UK more guidance. The Guts UK charity also provides useful information on various conditions.


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