Effect of fructose-reduced diet in patients with irritable bowel syndrome, and its correlation to a standard fructose breath test

Abstract

Objectives. To perform a validation of dairy registrations for use as diagnostic tool in IBS and fructose malabsorption (FM). To investigate the precision of the fructose breath test (FBT) as compared with symptom score reduction on fructose-reduced diet (FRD) in a cohort of patients with Rome II defined irritable bowel syndrome (IBS). Design. IBS patients diagnosed according to the Rome II criteria and with no organic gastrointestinal disease were enrolled. The patients were randomized in an open study design with a 2 week run-in on IBS diet, followed by 4 weeks w/wo additional FRD. FBT was performed in all patients. Dairy registrations of stool frequency and consistency as well as abdominal pain/discomfort and bloating on a visual analog scale (VAS) were performed during the whole study. Results. A total of 182 subjects performed the study according to protocol (88 FRD, 94 controls). The VAS symptom registration performed well in validation procedures, whereas stool data showed less impressive characteristics. FRD improved symptom scores (abdominal pain/discomfort and bloating) significantly whereas no changes were observed in the control group. The effect of FRD on the stool frequency was modest but no effect was observed on the stool consistency. The FBT did not discriminate between patients with and without effect of FRD, and even in the group with a negative FBT significant improvement of symptom scores was observed. Conclusion. VAS measures yield reliable symptom evaluation in dairy registrations of IBS. FRD improves symptom scores in IBS patients independent of results from the FBT.

Key Words::

• breath test
• dietary restriction
• fructose malabsorption
• functional bowel disease
• sugar intolerance

Acknowledgments

The authors would like to thank the research nurses Odd Sverre Moen Gastro lab, UNN for technical assistance and their colleagues at the Departments of Gastroenterology in recruiting patients for this study. Funding: The project was funded by the Northern Norway Regional Health Authority (Helse Nord RHF), the Gastro fund, University Hospital North Norway and Helgeland Hospitals Research Committee. Ethics Approval: The project was approved by the Regional Committee of Medical Ethics in North Norway (REK).

Declaration of interest: The authors declare no conflict of interest.

Supplementary Table 1.