Irritable Bowel Syndrome



Irritable bowel syndrome (IBS) is a relapsing functional bowel disorder in which abdominal pain or discomfort is usually associated with change in bowel habit. IBS is defined by diagnostic criteria based on specific symptoms following exclusion of the detectable organic causes. Further information can be found here


What are the typical symptoms?


Rome IV Criteria


Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria:

  1. Related to defecation

  2. Associated with a change in frequency of stool

  3. Associated with a change in form (appearance) of stool

Other Typical symptoms of IBS


Bloating and Wind – this usually presents with visible bloating and distension.

Diarrhoea- urgency (having to rush to the toilet), frequent and loose stools. People often needing to go to the toilet soon after eating.

Constipation – not able to open your bowels for a number of days and passing small pellet like stools.


Why do people suffer with IBS?


IBS is a very common condition, effecting approximately 1 in 5 people during the course of a year. It can present at any age, however, if more common in females during their 30-40’s.

The gut can be regarded as a long pipe surrounded by muscle and filled with nerve endings. There are more nerve endings in the gut than any other organ in the body. The cause of IBS is not known but there are a number of theories, which are discussed briefly below:


  • There appears to be a significant group of patients that develop IBS following an episode of gastroenteritis.

  • It is thought that weak contractions in the gut mean that food and stool isn’t propelled down efficiently, this causes constipation. Conversely, over-active contractions can lead to diarrhoea.

  • The nerve endings in the gut wall may become more sensitive to stretching resulting in pain.

  • Diet and lifestyle are thought to also contribute to symptoms.





A detailed clinical history and physical examination are important to identify any other possible diagnoses that need exclusion


Blood tests: To check the full blood count, inflammatory markers, coeliac screen and thyroid function tests.


If doctors wish to exclude other pathologies they may request other tests, including endoscopy or radiology examinations.




General dietary advice

  • Eating regularly and do not rush food.

  • Drinking plenty of fluids, aim to drink 2 litres of water a day

  • Caffeine can make symptoms worse; therefore, try to limit the number of cups of tea and coffee.

  • Decrease intake of fizzy (carbonated) drinks and alcohol

  • Also limiting high-fibre foods may cause symptoms.

A review by a dietician may help optimize your diet and also there is increasing evidence for a specific therapy called the FODMAP diet that may improve symptoms.


Specific treatments should be tailored to sub-types of different IBS and symptoms


Bloating/ wind

  • Symptoms may be improved by chewing and eating more slowly, since this leads to air swallowing.

  • Fizzy (carbonated) drinks – can cause bloating

  • Eating too much insoluble fibre may lead to bloating



  • Too much caffeine can be a stimulant leading to diarrhoea and loose stool

  • Low sugar gum – contains sorbitol which is a laxative

  • Alcohol – can cause diarrhoea

  • Too many vegetables – can lead to loose stool

  • Anxiety which can be improved with stress relieving techniques and cognitive behavioural therapy.

  • Avoid anti-inflammatory agents

  • Increasing rice intake will decrease water in the gut


Abdominal pain and discomfort

  • Some medications may help, such as mebeverine, buscopan and amitriptyline.

  • FODMAP diet.



  • Dietary fibre may help with constipation

  • Oats and golden linseeds may help.

  • Good fluid intake