4 different types of IBS and how to manage them

3rd June, 2024
Written by Jo Cunningham RD
How to Manage your IBS

IBS (Irritable Bowel Syndrome) is a common gut disorder that affects millions of us around the world. It could even affect up to as many as 1 in 3 of us in the UK (according to Guts UK). But even though lots of people experience IBS symptoms, many don’t seek the help and advice they deserve.

Here’s the lowdown on the 4 different types of IBS – and how you can start getting on top of symptoms.

First, a quick recap. What is IBS?

IBS is described as a disorder of the gut-brain connection, where the communication between the gut and brain isn’t working smoothly. This means your gut can be super sensitive (aka hypersensitivity), so certain foods can trigger tummy troubles. 

This can look different for different people. But the common complaints are tummy pain, bloating, gas and a change in bowel habits. There can also be feelings of urgency (you need to go *right this second*) or incomplete evacuation (when you don’t feel like you’ve completely emptied). Other symptoms can include heartburn and reflux, as well as headaches, anxiety and fatigue.

The 4 types of IBS?

There are four main categories of IBS – depending on your main symptoms and where your poo lies on the Bristol Stool Chart (see below). Here’s the criteria for each from the Rome Foundation, who developed the Rome IV Criteria to diagnose IBS.

1. IBS with Constipation (IBS-C)

This is when at least a quarter (25%) or more of your bowel movements are hard or lumpy stools – and look like types 1 or 2 on the Bristol Stool Chart. Less than a quarter of your poos will be loose (types 6 or 7 on the chart).

2. IBS with Diarrhoea (IBS-D) 

This is when a quarter or more of your poos are loose or watery, like diarrhoea (types 6 or 7 on the chart). You’ll likely feel the urge to poo frequently.

3. IBS with Mixed Bowel Habits (IBS-M)

People with IBS-M have both constipation and diarrhoea and alternate between the two. The clinical criteria is more than 1 in 4 poos are constipated (types 1 or 2), and more than 1 in 4 poos are diarrhoea (types 6 or 7).

4. IBS Unclassified (IBS-U)

This type is when your bowel habits don’t really fit neatly into any of the three other categories – and having both diarrhoea and constipation is rare.

Bristol Stool Chart

Source: NHS

The Bristol Stool Chart shows the different types of poo. Types 1-2 = hard stool and constipation. Types 3-4 = ideal, easy to pass poo. Types 5-7 = loose stools and diarrhoea.

How do I know if I have IBS and which type?

To get an IBS diagnosis, certain tests are recommended to make sure your gut symptoms aren’t down to another condition first. These tests could include:

  • A full blood test to check for anaemia or infection
  • A blood test to check for inflammation, known as an ESR (Erythrocyte Sedimentation Rate) or Plasma Viscosity, and checking levels of a marker of inflammation called C-reactive Protein (CRP)
  • A test for coeliac disease* and inflammatory bowel disease (IBD)

*If you’re getting checked for coeliac disease, you need to be eating gluten daily for an accurate result. Otherwise, you might get a false negative which is potentially a missed diagnosis.

You might be recommended to have more tests by a dietitian or gastroenterologist, depending on what’s right for you personally.

What causes IBS?

There’s no single ‘cause’ for IBS (it’s more complex than that!) – but there are several common factors. Understanding your own triggers can help you find the right treatment strategy for you.

  • A change in gut movement. A dysregulated nervous system (like with stress and anxiety), hormonal imbalances, poor diet or some medications can make your digestive tract muscles contract more or less than normal. This can impact your bowel movements.
  • Gut microbiome changes: Differences in your mix of microbes can impact your digestion, as well as your immune response. A bunch of things affect your microbiome, like antibiotic use, your diet and infections – leading to an imbalance of bacteria in your gut. 
  • Gut infections. Like salmonella, E.coli and other bacterial infections, as well as viruses like norovirus and rotavirus can make developing IBS more likely. It’s called ‘post-infectious IBS’. 
  • Gut sensitivity (visceral hypersensitivity): This is when you have a stronger experience of pain or discomfort from normal gut sensations. It can be caused by things like inflammation of the gut lining, changes in your nervous system and how it processes pain signals, stress, anxiety, as well as your gut microbiome.
  • Genetics: IBS can run in families, so it seems like there’s a hereditary part to it. But the link between our genes and the influence of our environment in IBS is still being researched.

For IBS-C:

  • Daily kiwi. A study has found that 1-2 kiwifruits per day can be as effective as a bowl of prunes for getting things going. 
  • Constipation-approved probiotics: Specific probiotics could help with specific constipation symptoms. It’s about matching the strain to your symptoms, so head over to the Reviews to find probiotics trusted for constipation.
  • Look at laxatives. Some laxatives can help to get things moving and improve your bowel habits. Note that not all laxatives are equal! Some can cause the gut to become more lazy in the long run so we need to choose the right laxative type for you. Check with your dietitian, GP or speak with your local pharmacist before taking any laxatives.

For IBS-D:

  • Check common culprits. Try reducing the amount of caffeine, spicy food, fatty food and alcohol you’re having, as they can all trigger symptoms. 
  • Limit high FODMAP foods, but don’t do this alone. This is one IBS type where the low FODMAP diet could be helpful. FODMAPs are types of carbohydrates that are highly fermentable, so they can trigger IBS symptoms. Foods especially high in FODMAPs include garlic, onion, wheat, kidney beans (and other pulses), as well as many fruits and vegetables like apples, mangoes, dried fruit, artichoke, leeks and cauliflower. This doesn’t mean these foods are ‘bad’ (they’re actually really nutritious!), but a break for a few weeks of these types of foods can help reduce symptoms and gut sensitivity. Always get the help of a qualified IBS specialist dietitian before restricting your diet to make sure 
    1. The low FODMAP diet is appropriate for your particular case
    2. you’re not missing important nutrients 
    3. getting all the fibre you still need.
  • Anti-diarrheals. These can improve diarrhoea symptoms and help you take control of loose poos. Your dietitian can talk to you about the optimal time to take these, or chat to your GP or pharmacist to see if this is right for you.

Always check with your healthcare provider before starting any new medication or supplement.


About Jo Cunningham RD, Gut & IBS specialist dietitian and founder of Green Light Nutrition

Jo Cunningham is an award-winning dietitian specialising in IBS and other gut health conditions, as well as cancer nutrition. Offering 1:1 consultations in person and online with her team at Green Light Nutrition. Jo also runs a comprehensive IBS Relief Programme designed to empower you with the tools to effectively manage your IBS symptoms, so your IBS stops holding you back.

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