Are There Different Types of IBS? - Chromatography Investigates

Irritable bowel syndrome (IBS) is a chronic disease-causing abdominal pain or discomfort and a change in bowel habit. In many patients it can be a life-long illness that is subject to many periods of relapse. Currently there is no cure and patients have to control the symptoms through changes in diet and lifestyle.

There are several subtypes of IBS, can chromatography help researchers use the differences to find a treatment? A recent study published in the Journal of the Canadian Association of Gastroenterology has investigated whether it is possible to use microbial analysis and metabolomics to distinguish between the types and the pain they cause.

IBS - more than an irritation

IBS is a relatively common condition that could affect up to 1 in 8 people at some point in their life. It is a condition that affects the digestive system and can last a lifetime. It causes symptoms including stomach cramps, bloating, diarrhoea and constipation. Patients have to rely on diet changes and some medicines to control their symptoms as there is no cure presently. The exact cause of irritable bowel syndrome is unknown. Genetic factors are not thought to play a role, and common triggers to a first bout include food poisoning or gastroenteritis.

Types of IBS

Irritable bowel syndrome can be broken down into three subtypes:

• IBS with constipation - patients suffer stomach pain, bloating, delayed or infrequent bowel movement, or hard stools.
• IBS with diarrhoea - patients suffer with stomach pains and discomfort, frequent bowel movements often with an urgent need, loose and watery stools.
• IBS with both constipation and diarrhoea.

There are about equal numbers of patients with each type of IBS, and indeed evidence suggests that patients can switch between types. This makes it difficult for researchers to develop drugs and treatments that can help patients with the symptoms of IBS. The medications that work for IBS with constipation are different for the treatments for IBS with diarrhoea.

Chromatography separates the microbes

In the work recently carried out in Canada, researchers collected stool and urine samples from 30 patients with IBS-diarrhoea and 30 patients with IBS-constipation along with healthy controls. They analysed the samples for metabolites using liquid chromatography-mass spectrometry. The use of chromatography to analyse biological samples is discussed in the article, Online Solid Phase Extraction and LC/MS Analysis of Thyroid Hormones in Human Serum.

The researchers found that both types of IBS patients had different microbiota compared with non-IBS patients. The different metabolomic and bacterial profiles between the samples suggests that it might be possible to define the subgroups based on phenotype. However, further studies are needed to determine if there are differences between the subgroups and healthy controls.