Frequency and predictors of fructose malabsorption in patients with functional abdominal pain syndrome: A case-control study

BACKGROUND Functional abdominal pain syndrome (FAPS) is a subset of functional gastrointestinal disorder characterized by chronic recurrent abdominal pain condition that is not attributable to structural, organic, or metabolic diseases. The etiology and pathophysiology of FAPS remain poorly understood; however, brain-gut interactions and food intolerance, particularly to fermentable oligo-, di-, and monosaccharides and polyols, have been implicated. AIM To determine the frequency of fructose malabsorption (FM) in patients with FAPS and to evaluate the occurrence of resultant symptoms. METHODS This was a prospective, case-control study conducted over 22 months, from December 2016 to September 2018, at the Department of Gastroenterology, Govind Ballabh Pant Institute of Postgraduate Medical Education and Research, New Delhi, India. In this study, 61 patients with FAPS and 31 healthy controls underwent fructose hydrogen breath testing (FHBT) after excluding small intestinal bacterial overgrowth. RESULTS FM was detected in 26% of patients with FAPS vs 3% of controls (P = 0.009). Symptoms during the FHBT were significantly more prevalent in patients with FAPS (39.3%) than in the controls (12.9%) (P = 0.009). Among patients with FAPS, those with positive FHBT results had a higher prevalence of symptoms (62.5%) than those with negative results (31%) (P = 0.03). Multivariate analysis identified younger age (P = 0.012) and male sex (P = 0.049) as predictive of a positive FHBT result. Methane producers were present in 37% of patients with FAPS, with no difference between those with and without FM. CONCLUSION This study demonstrated a high prevalence of FM and intolerance in patients with FAPS, with younger age and male sex as predictors.