Understanding your IBS subtype

Reviewed by Bridgette Wilson

Irritable bowel syndrome (IBS) is one of the most common gut issues reported to GPs and gastroenterologists (1), but did you know that IBS is further broken down into four different subgroups?

The subtype of IBS you have is determined by your poop. Different subtypes need different types of treatments so it’s important to take notice of your poop when you’re visiting the toilet. The four subtypes are: IBS diarrhoea (IBS-D) when your poop is mainly loose and rarely hard, IBS constipation (IBS-C) when your poop is mainly hard and rarely loose, IBS mixed (IBS-M) when your poop is a mixture of loose and hard, and IBS unclassified (IBS-U) when your poop is normal (formed like a sausage or small soft blobs and easily passed) (2).

Where to start?

Taking notice of how much, how little, how soft, or how hard your poo is on a daily basis isn’t something to be embarrassed about, but a really important step to understanding your gut health. Pooing is a natural process and in fact, you’ll be surprised by how much it can say about what’s going on inside of you – and importantly here, what subtype of IBS you might have.

Let’s start with diarrhoea predominant IBS (IBS-D)

Do you often find that eating certain foods or a particularly large meal puts your gut into knots and has you running to the toilet? Or perhaps you have some worries about an upcoming deadline at work, which sends you into a frenzy of abdominal pain, bloating and frequent pooing throughout the day? This is characteristic of IBS-D.

One-third of people with IBS have IBS-D. This means your poo is often on the runny side and contains too much liquid. This usually happens when your intestines contract rapidly and push digested food through the gut much faster than normal, reducing the time that water can be absorbed (4). Not only are these contractions painful and off-putting, but they can often lead to a sudden urgency to use the bathroom - which is never ideal when you’re out of the house.

Next in line is constipation predominant IBS (IBS-C)

If you suffer from IBS-C, then you’ll experience the complete opposite. Your gender can play a role, as IBS-C has a far higher occurrence in women than it does in men. Research suggests that this could be due to the differences in sex hormones and body physiology (5), which as a result, can lead to a slower bowel.

With IBS-C, the contractions of your intestines are considered ‘lazy, so it takes a lot longer for digested foods to move through the system - causing pain, bloating and gas. This can be uncomfortable and make you feel sluggish due to the length of time it takes for you to pass any poo. Even if you manage to poo diy, if the stool is dry and hard this indicates it’s taken a long time to pass through the gut and so it’s likely your bowel is still backed up with plenty of poo.

Think of a tube of cotton wool, if you push at one end some comes out the other end but this doesn’t mean the tube is empty. The bowel can be like this when you’re constipated with small amounts exiting each day, but you never really get a good clear out. Straining and unsatisfactory relief when pooing – i.e. you’ll feel like you haven’t ‘gone’ properly – is extremely common, and this can be particularly frustrating if you’ve suffered from constipation for long a time.

Then there’s mixed type IBS (IBS-M)

IBS-mixed, as the title suggests, is characterised by a mixture of the previous two subtypes, i.e.:

• Over a quarter of your poos are hard and lumpy (constipation)
• And over a quarter of your poos are loose or watery (diarrhoea)

It’s important to seek support and understand what will help you effectively manage these changes in symptoms.

And finally, there’s IBS unclassified (IBS-U)

IBS-U is characterised by symptoms such as abdominal pain or discomfort that may be associated with changes in the frequency of pooing but with mostly normal looking poo (Bristol Stool Chart type 3-5).

It’s important to seek support and understand what will help you effectively manage these changes in symptoms.

Despite the differences

IBS affects the quality of life no matter what the subtype. Access to appropriate support and improving your understanding of your condition and what works for you, are key to effective self-management.