Constipation and faecal incontinence: SAQ

This boy has functional constipation with retentive faecal incontinence. The apparent loose leaking is overflow of liquid stool around a hard rectal impaction, confirmed by the once-weekly enormous stools, the withholding posture, and the palpable faecal mass, with a normal examination and no red flags allowing a positive diagnosis. ^[1]

Question 1 (10 marks)

Explain why this child soils, how you would confirm the diagnosis, and which features would make you consider an organic cause. ^[1]

The soiling is retentive faecal incontinence, an involuntary overflow of soft stool that tracks around a hard impaction and leaks through an anus the child can no longer keep closed. Chronic withholding has stretched the rectum into a low-tone megarectum that no longer signals fullness, so the child cannot feel the leakage and is not being naughty. The diagnosis of functional constipation is clinical, resting on the typical history of infrequent large stools and withholding, the palpable faecal mass, and a normal examination, and it can be made positively using the Rome IV criteria without routine blood tests or an abdominal radiograph. I would actively screen for red flags that point to an organic cause: constipation or delayed meconium from the first weeks of life, ribbon stools, abdominal distension with bilious vomiting, growth faltering, an abnormal anus or sacral dimple, and abnormal lower limb neurology or anal wink, all of which would prompt consideration of Hirschsprung disease, a spinal lesion, or another organic diagnosis. I would also keep safeguarding in mind for any child with unexplained soiling. ^[1]