The exact cause of IBS is not known. However, most experts agree that there are factors that may trigger, or worsen symptoms. These include:

Diet

• Large meals, or food containing a large amount of fat can upset the bowel.
  
  
• Find out more about common foods that can trigger IBS symptoms: Balanced diet.

Stress and anxiety

• Your bowel will respond to stress and anxiety, which in the IBS sufferer often results in constipation or diarrhoea.
  
  
• Try some anti-stress techniques to reduce the impact of stress and calm symptoms: Yoga exercises.

Female hormones

• Experts have found that symptoms can be worse when a woman has her period, which suggests hormones play a role in the condition.

Medicines

• Certain medicines such as iron tablets, some painkillers and antibiotics, can upset the bowel and produce symptoms of IBS.