Irritable bowel syndrome symptoms include recurrent abdominal pain or discomfort that is associated with a change in stool frequency or form. The pain or discomfort may be relieved by defecation.
It is important to determine whether there are any dietary associations such as lactose-containing foods or fructose-containing foods.
Examination of the abdomen is usually unremarkable. There may be mild and poorly localised tenderness in the right lower quadrant and/or left lower quadrant.
The diagnosis is based on the patient's history, and there are no specific diagnostic tests. If the patient has worrying symptoms or findings such as anaemia, weight loss, or fever, then these require more thorough investigation.
Treatment should be individualised and is dependent on the patient's predominant symptoms.
Irritable bowel syndrome (IBS) is a chronic condition characterised by abdominal pain associated with bowel dysfunction. The pain is often relieved by defecation and is sometimes accompanied by abdominal bloating. There are no structural abnormalities to explain the pain. IBS occurs in about 15% of the adult population. The aetiology is probably multi-factorial and evidence suggests motility, inflammatory, genetic, immune, psychological, and dietary components. 
Chief of Gastroenterology and Hepatology
Clinical Professor of Medicine
Baylor College of Medicine
Adjunct Professor of Medicine
University of Texas Medical Branch
NS declares that he has no competing interests.
Professor of Medicine and Psychiatry
School of Medicine
UNC Center for Functional GI and Motility Disorders
DD declares that he has no competing interests.
Department of Gastroenterology
St Mark's Hospital
SM declares that he has no competing interests.
Clinical Research Fellow
Division of Medicine
HW declares that he has no competing interests.
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