The ACG Clinical Guidelines suggest that a positive, conclusive diagnosis of IBS should be made as opposed to a diagnosis of exclusion. In addition, testing for coeliac disease and inflammatory bowel disease should be completed for patients with IBS and diarrhoea symptoms. A short trial of a low FODMAP diet and gut-directed psychotherapy are recommended to improve global symptoms, rifaxamin use for diarrhoea-predominant symptoms and various pharmacological options for constipation-predominant symptoms. Pathogenic stool testing, probiotic use and faecal microbiota transplant are recommended against.