Bowel transit studies in children: evidence base, role and practicalities.

Constipation is common in children and adults with varied worldwide prevalence. The majority of children have functional constipation as defined by Rome clinical criteria and respond favourably to standard medical therapy; up to one-third can develop difficult-to-treat constipation requiring investigation and specialist treatment. Colon function tests aim to assess the neuromuscular integrity, the movement of faeces across the colon and evaluate/predict response to the therapy. The 'ideal' test should be practical, non-invasive, widely available and cost-effective. None of the available diagnostic tools is designed to provide a comprehensive assessment of colon function and clinicians often have to combine more than one test to answer different questions. In this review, we aim to assess the strengths and limitations of the commonly available diagnostic investigations (radiopaque marker studies, scintigraphy, wireless motility capsule and colonic manometry) used to assess colon transit in children and to provide guidance on the most appropriate test for particular clinical settings.