The investigation of chronic diarrhoea: new BSG guidance.

Abstract

Chronic diarrhoea has an estimated prevalence of about 4–5% in Western populations and is one of the most common reasons for gastroenterology referral.1 There is a myriad of causes for chronic diarrhoea, which can make the investigation and diagnosis of the underlying cause difficult. In 2003, the British Society of Gastroenterology (BSG) released guidelines2 to aid in the investigation of chronic diarrhoea; however, these have since been updated, in April 2018. Below, we provide a brief and focused summary of the new 2018 guidelines1 for primary care, highlight the new changes compared with the 2003 edition, and discuss some limitations of the new guidance. Initial investigations in primary care are aimed at differentiating organic gastrointestinal (GI) disease from functional disease. Routine, screening blood tests are recommended in all patients presenting with chronic diarrhoea, and these include full blood count, ferritin, c-reactive protein, coeliac serology, and thyroid function tests. Faecal calprotectin (FCP) is now recommended as a screening tool to detect inflammatory causes of chronic diarrhoea, and stool cultures remain useful in distinguishing infection from other inflammatory causes of chronic diarrhoea. Faecal immunochemical testing (FIT) is a new method of detecting the presence of blood in faeces and can be used instead of the traditional faecal occult blood test (FOBT) where available. In general, for patients with typical symptoms of functional bowel disease, normal physical examination, and normal screening investigations, a diagnosis of IBS can be made. However, referral should be considered for those with abnormal screening investigations or persistent symptoms that impact the quality of life and do not respond …