Functional abdominal pain and irritable bowel syndrome: Viva

Branch 1: History, Rome IV criteria, and distinguishing functional from organic disease

The candidate should acknowledge the parents' worry and then take a structured history rather than immediately ordering a colonoscopy. Characterise the pain by site, timing, and its relationship to defecation, and establish the stool form and frequency using the Bristol stool scale, noting that pain relieved by opening the bowels with a change in stool pattern meets the Rome IV criteria for irritable bowel syndrome. The predominant loose stools would make this the diarrhoea subtype. The key task is to screen actively for alarm features: weight loss or growth faltering, rectal bleeding, night waking, nocturnal diarrhoea, fever, joint or mouth symptoms, and the family history of inflammatory bowel disease. [2]

A strong candidate recognises that the relative with Crohn disease raises the pre-test probability of inflammatory bowel disease and therefore lowers the threshold for a faecal calprotectin, but that it does not by itself justify colonoscopy in a well, thriving child. Equal weight should go to the psychosocial history, especially the link with exams, and questions should be framed as routine so the family does not feel accused. If the pattern is typical, growth is normal, and no alarm features are present, the candidate should be prepared to make a positive IBS diagnosis. [1]

Branch 2: Investigation and the request for a colonoscopy

If the examiner presses on the parents' request for a colonoscopy, the candidate should explain that investigation must be targeted. A reasonable first-line screen includes a full blood count, inflammatory markers, coeliac serology with total immunoglobulin A, a urinalysis, and a faecal calprotectin, which is the pivotal test here because it separates irritable bowel syndrome from inflammatory bowel disease non-invasively. Stool studies for giardia are added if the history fits. [2]

The candidate should justify why colonoscopy is not first-line in a well, thriving child without alarm features, but should also state clearly that a raised faecal calprotectin, weight loss, rectal bleeding, or nocturnal diarrhoea would change that and prompt referral for endoscopic assessment. A good answer names the negative-test spiral: repeated normal investigations can deepen rather than relieve family anxiety, so after a normal targeted screen the correct step is a positive diagnosis and treatment, with a low threshold to re-investigate if the pattern changes. [2]

Branch 3: Management and counselling

If asked about management, the candidate should build the plan on a positive diagnosis delivered with a clear biopsychosocial explanation: the pain is real, the gut-brain connection has become oversensitive, serious disease has been sensibly excluded, and IBS is genuine but benign. A return to normal school and activity, including sitting exams with a coping plan, is part of the treatment. The candidate should describe lifestyle and dietary measures and a time-limited, supervised low-FODMAP trial for the diarrhoea-predominant symptoms. [1]

For persistent or disabling symptoms, the candidate should recommend psychological therapy, explaining that gut-directed hypnotherapy produced durable benefit over standard care in a randomised trial and that cognitive behavioural therapy also helps, both treating the gut-brain mechanism rather than implying the pain is imaginary. Peppermint oil is a reasonable pharmacological option for IBS symptoms, and any tricyclic is used selectively given the large placebo response in trials. The candidate should finish with function-focused follow-up, school liaison, and clear safety-netting, pairing confident reassurance with ongoing vigilance. [3]