Our aim was to assess the use of a low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet in children with different types of functional abdominal pain disorders (FAPD) and to identify predictive factors of response to this diet.

This was a multicenter, experimental, uncontrolled, prospective trial. Patients with irritable bowel syndrome (IBS), functional dyspepsia, and functional abdominal pain followed a low FODMAP diet for 2 weeks. We collected data on abdominal pain before and after the diet. Patients who showed a ≥ 50 % reduction in abdominal pain frequency were considered responders.

A total of 48 patients with FAPD participated in this trial. They all showed a significant decrease in the frequency (p < 0.05) and intensity (p < 0.05) of abdominal pain after the diet. We considered 41.7 % of patients to be responders. Among children with functional dyspepsia, 66.6 % responded to the diet, and so did 71.4 % of those with IBS. On the contrary, 71.8 % of children with functional abdominal pain were non-responders, and this diagnosis was considered a predictive factor of poor response to the diet (OR: 9.87, CI [1.52; 63.97], p = 0.016).

In children with FAPD, a diagnosis of functional abdominal pain is a predictive factor of poor response to a low FODMAP diet. Better results were achieved with this diet in children with IBS or functional dyspepsia.