Functional abdominal pain and irritable bowel syndrome: SAQ

This girl fits the Rome IV picture of irritable bowel syndrome: recurrent abdominal pain relieved by defecation, a change between hard and loose stools, bloating, and a well child with normal growth and examination. The absence of alarm features and preserved growth allow a positive diagnosis, and the mixed stool pattern places her in the IBS-M subtype. ^[1]

Question 1 (10 marks)

Explain how the Rome IV criteria let you make a positive diagnosis of irritable bowel syndrome in this child, and outline the investigations you would arrange. ^[2]

Irritable bowel syndrome is diagnosed positively when recurrent abdominal pain is related to defecation and is accompanied by a change in stool form or frequency, present over an adequate period without alarm features. This girl meets that pattern: pain relieved by opening her bowels, stools swinging between hard and loose, and bloating, with a well appearance, normal growth, and a normal examination. Her mixed hard and loose stools make this IBS-M, and the subtype is judged from the abnormal stools using the Bristol stool scale and reassessed over time. Because the pattern is typical and there are no alarm features such as weight loss, rectal bleeding, night waking, or nocturnal diarrhoea, this is a positive diagnosis rather than one reached by exhausting every organic possibility. ^[1]

Investigation should be targeted. A reasonable first-line screen includes a full blood count, C-reactive protein and erythrocyte sedimentation rate, coeliac serology with total immunoglobulin A, a urinalysis, and a faecal calprotectin, which is especially useful here to separate irritable bowel syndrome from inflammatory bowel disease given the diarrhoeal component. Stool studies for giardia are added if the history suggests infection. Endoscopy, colonoscopy, and imaging are reserved for alarm features or an abnormal screen, because over-testing a well child rarely changes the diagnosis and reinforces the search for disease. ^[2]