What is IBS?

IBS is a medical term used to describe a collection of gut symptoms not explained by any other disease. Symptoms can include diarrhoea, constipation, bloating, abdominal pain, cramping and wind.

These can vary from person to person and also in the same person at different times, often in response to changes in diet, lifestyle or stress levels.

There are different types of IBS which are classified according to the main symptom. These include: IBS-D (where diarrhoea is the main symptom), IBS-C (where constipation is the main symptom), IBS-M (where symptoms are mixed) and IBS-U (unspecified). IBS-D is the most common type affecting more than 50% of people with IBS.   IBS can have a significant impact on the quality of life of those with the condition. Around half of those with IBS have been found to suffer from anxiety or depression. 

How common is IBS?

IBS is one of the most common gut-related reasons for people to visit their GP. It is thought to affect up to 20% of the UK population and is most commonly diagnosed in women aged between 30-50 years. It usually develops in early adulthood and persists on and off throughout life. 

What causes IBS?

The cause of IBS is not fully understood. Studies have shown that the gut of people with IBS tends to be more sensitive and reactive. A hectic lifestyle, anxiety and stress can all affect the gut which may increase symptoms. For some people, IBS may follow a serious stomach bug (gastroenteritis) or a course of strong antibiotics to treat other conditions. Others may develop IBS following a traumatic life event or change.   

How is IBS diagnosed?

There is no test to diagnose IBS. Symptoms can be very similar to other gastrointestinal (gut) conditions and so before a diagnosis of IBS is confirmed, it is important that other serious gastrointestinal conditions such as coeliac disease, inflammatory bowel disease, as well as other bowel and gynaecological conditions, are first ruled out.  

  • If you have any ‘red flag’ symptoms that are not usually associated with IBS, it is important to consult with your GP in the first instance.
  • If your symptoms are relieved by defaecation (going for a poo), or are associated with a change in your bowel habits, then a diagnosis of IBS should be considered once all other possible causes have been ruled out.

Red Flag Symptoms

  • Change in bowel habit to looser and/or more frequent stools persisting for more than six weeks in a person aged over 60 years
  • Passing blood from the back passage
  • Unintentional and unexplained weight loss
  • Family history of bowel or ovarian cancer

What tests might my GP do?

Your GP should perform a simple blood test to screen for coeliac disease (link to coeliac disease page on Schar website), an autoimmune condition with similar symptoms to IBS. In addition, other tests may be undertaken to rule out other conditions such as inflammatory bowel disease. Following a full assessment your GP may refer you to a gastroenterologist (a specialist in bowel disorders) at the local hospital for further investigations or advice.

You may be diagnosed with IBS if your abdominal pain is either relieved by opening your bowels or is associated with altered stool frequency or form, and is present with at least 2 of the following;

  • Altered stool passage
  • Abdominal bloating
  • Symptoms made worse by eating
  • Passage of mucus

Other symptoms including lethargy, nausea, backache and bladder symptoms are common in people with IBS and can be used to support the diagnosis.

Many patients with IBS report their symptoms get worse after eating. Visit our IBS Dietary Advice page for more information.