Differentiation between irritable bowel syndrome from inflammatory bowel disease flare-up through gut microbiota assessing test in quiescent IBD patients with IBS-like symptoms

Abstract

Background IBD is a chronic relapsing disorder and represent a huge burden in the life of the individuals suffering from it. Moreover, once achieved the remission state, known as quiescent IBD, around one third of the patients will still present intestinal symptoms compatible with IBS (IBS-like symptoms). Even if both entities are well-defined and differentiate, in quiescent IBD patients with persistent clinic the diagnosis is not easy established through anamnesis and examination alone, and in most cases a colonoscopy is performed in order to confirm the origin of the symptoms. Therefore, there is a need for a non-invasive diagnostic test to differentiate between both entities without the performance of unnecessary colonoscopies. RAID-Dx is a new diagnostic tool based on the detection of the alteration on the main gut microbiota populations related to IBS and IBD from a stool sample. As IBS and IBD both have its own microbiological signature, this test has emerged as a potential, and inexpensive, alternative to colonoscopy in the assessment of IBS-like symptoms in patients with quiescent IBD.

Objectives The main purpose of the study is to verify RAID-Dx test as an optimal diagnostic tool for the differentiation of IBS and IBD flare-up in patients with quiescent IBD suffering from

IBS-like symptoms. For that reason, sensibility, specificity, PPV, PNV and likelihood- ratios will need to be established. Secondary objectives include the assessment of diet

as an interaction factor of RAID-Dx results and the calculation of IBS prevalence in qIBD patients.

Design and Methods This is a cross-sectional study performed in 6 different centres located in Girona, Figueres and Olot sanitary areas. The number of participants needed to recruit is 207

patients, from March to September 2020, and the sampling obtention follows a non- probabilistic consecutive design method. Bivariate analyses have been used to

investigate potential associations between RAID-Dx results and various demographic, disease factors and diet habits