What are the different types of IBS?

What are the different types of IBS?

IBS symptoms tend to flare up intermittently. The Rome Foundation, an organisation that defines, researches and classifies functional conditions and gastrointestinal disorders such as IBS, has managed to divide the condition into four different sub-types. These are defined by the consistency of the stool during an IBS flare-up.

Being able to identify the type of IBS a person has makes it easier for a doctor to pinpoint what the possible triggers are. This helps him/her to prescribe effective medication when treating IBS. In addition to medication, the sufferer will also be able to:

  • Enforce dietary changes needed by detecting which foods are triggering IBS symptoms.
  • Avoid situations that cause stress as this may cause the gut to react negatively.
  • Take prescrition medications to relieve diarrhoea and laxatives for constipation.

Types of IBS

The following are the four sub-types of IBS that have been identified:

  • IBS characterised by constipation is known as IBS – C (the ‘C’ stands for constipation).
  • The same thinking is applied to IBS with diarrhoea which is referred to as IBS – D.
  • When people have a pattern of IBS with alternating bouts of diarrhoea and constipation, this is known as IBS – M (mixed IBS).
  • If symptoms do not fit into the classifications above, the person's condition may be referred to as IBS – U, this is unsubtyped IBS.

The types are further explained as follows:

IBS-C: IBS with constipation

This type of IBS often results in hard stools that may be difficult or painful to pass over 25% of the period of the IBS flare-up. It is also possible for sufferers to experience watery stools and diarrhoea for 25% or less of the time. However, the identifying factor is the predominant constipation.

A doctor is likely to conduct imaging tests in order to detect rule out any anatomical abnormalities (abnormal structures that are in an odd location or have an inconsistent or strange shape) in the gut before making a concrete diagnosis.

Those suffering from IBS-C will generally be advised to include more fibre in their diets as well as whole grains in order to soften stools and allow them to pass more easily. If necessary, a bulking agent may be prescribed to aid this process.

IBS-C symptoms

IBS-C symptoms may include:

  • Small, dry and hard stools associated with constipation.
  • Pain in your abdominal region, this often includes sharp stabbing sensations and cramping.
  • Constantly feeling like you need to go to the toilet.
  • Feeling bloated and gassy, particularly after certain foods.
  • Mucus in your stool.
  • Internal haemorrhoids may result due to having to strain during a bowel movement and this may result in anal bleeding when you go to the toilet.

A doctor is likely to prescribe the use of laxatives to help relieve constipation, he/she may prescribe something stronger than over-the-counter drugs to treat this form of constipation such as Lubiprostone (Amitiza) – which helps to treat chronic constipation.

IBS-D: IBS with Diarrhoea

With this type of IBS, sufferers experience loose, watery stools associated with diarrhoea for more than 25% of their IBS flare-up. Constipation is not typically experienced with this type of IBS.

A doctor will often suggest eating smaller meals more frequently, as well as avoid certain foods that may trigger diarrhoea. Spicy foods, dairy and artificial sweeteners should typically be avoided.  

Symptoms of IBS-D

Symptoms may include:

  • Abdominal pain
  • Bloating
  • Suddenly needing to go the toilet
  • Having no bowel control
  • Gas
  • Loose, watery stools

Stress and other psychological traumas are often triggers for diarrhoea. Wheat, dairy, red wine and caffeine have also been known to trigger it. IBS–D can be a very embarrassing and uncomfortable condition for sufferers and this can cause a degree of anxiety. Doctors often prescribe antidiarrheal medications and lifestyle changes in managing IBS-D (discussed in detail in the treatment section of this article). 

IBS-M: Mixed type IBS

A few people with IBS do not definitively experience one of the above-mentioned types of IBS. If a sufferer experiences alternating bouts of constipation and diarrhoea, they will fall into the IBS-M category.

This means diarrhoea and constipation are experienced during the same flare-up. In this case, triggers will need to be identified in order to balance treatments. Dietary changes, avoiding stressful situations, and being prescribed anti-diarrheal medications as well as laxatives will help ease the symptoms of abdominal pain, gas and bloating, as well as diarrhoea and constipation. 

Unsubtyped IBS (IBS-U)

If IBS symptoms experienced do not fit into any of the above-mentioned categories, this may be classified as IBS-U.

IBS-U symptoms

This type of IBS is known to include the following symptoms:

  • Gas
  • Cramping
  • Bloating
  • Mucus in the stool
  • Abdominal pain and discomfort

What makes this type of IBS different is that people who fall into this category are not likely to experience irregularities in their stool.

PREVIOUS What are the symptoms of IBS?
NEXT What causes IBS?