Irritable bowel syndrome is a chronic intestinal disease. It is very common and causes bloating, abdominal pain, diarrhea, or constipation. It is often accompanied by other symptoms such as headaches, fatigue, general pain... Women are more frequently affected by irritable bowel syndrome than men. The clinical examination of the patient rarely identifies objective signs and additional biological or imaging tests sometimes miss abnormalities. Generally the cause of irritable bowel syndrome is not determined: it could be a psychosomatic illness (somatic symptoms from a psychological cause).