The 4 IBS subtypes
Nearly all of us have been affected by or know someone affected by a gut problem, and irritable bowel syndrome (IBS) is common among these.
IBS is the name given to a complex condition that is typically characterised by abdominal pain, bloating and altered bowel habits (constipation/diarrhoea). IBS is what we call a ‘functional’ gut disorder. This means that there is no obvious disease in the gut. Rather, IBS affects the way the gut works. The ‘motility’ or movement of the gut is altered. As a result, movement may be sped up, resulting in diarrhoea, or slowed down, resulting in constipation.
As many as 30-40% of people with IBS will experience ‘visceral hypersensitivity.’ This means that these people are particularly sensitive to any gas or pain in the bowels. These people may experience abdominal pain and bloating.
So, with the range of potential IBS symptoms, it’s no surprise that the way people experience IBS can be very different.
The IBS subtypes
If you are diagnosed with IBS, it is important that you, your doctor and your dietitian determine what IBS subtype you are. As a result, they can help you to manage your IBS appropriately. The main subtypes are:
1. IBS-C (Constipation predominant)
- Infrequent movements (~<3/week).
- Hard stools.
- The sensation of blockage and straining.
2. IBS-D (Diarrhoea predominant)
- Frequent bowel movements (~>3/day).
- Loose stools.
- Sense of urgency (you need to go NOW!).
But wait… I experience both these symptoms!?
3. IBS-M (Mixed) – A combination
4. IBS-U (Unspecified) – Just not sure.
Pain, gas and bloating may be additional symptoms that occur within any of these types.
Your dietitian may ask you to keep a food and symptom diary to help determine your sub-type. Additionally, medications can make it difficult to determine the sub-type, so you may be asked to stop those that are not essential for a short time.
How does the sub-type change the treatment?
The main ways that sub-type will change treatment are via:
- Type of medication: Aperients (relieve constipation) VS antidiarrheals, as well as the type of probiotic strain that may be useful.
- Type of fibre: In IBS-C an increase in all fibre types may be helpful, while in IBS-D insoluble fibre may make symptoms worse. Soluble fibre may assist in both cases e.g. psyllium husk.
- Caffeine and alcohol may be more problematic for those who experience IBS-D.
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Reviewed by the healthylife Advisory Board March 2022