The inulin hydrogen breath test accurately reflects orocaecal transit time.

Background: The lactose[(13)C]ureide breath test ((13)C-LUBT) has been validated and established as a reliable, non-invasive test for the assessment of orocaecal transit time (OCTT). More recently, small studies have demonstrated that inulin could be an alternative substrate for H(2)-based breath testing of the small bowel transit (H(2)-INBT). We compared the performance of the H(2)-INBT with the (13)C-LUBT in an appropriate number of participants, determined by sample-size calculation.