Study Procedure

All inpatients and/or outpatients presenting to the Department of Internal and Integrative Medicine, Clinics of Essen-Mitte, Germany for UC treatment between 2002 and 2017 were invited to participate. Two research coordinators (A.O. and Dorit Schroeder) approached patients who were provided information about our department’s research. Interested patients gave their written consent to the use of their medical data for use in prospective research at the clinics in Essen-Mitte and were scheduled for a colonoscopy and stool sample collection. For this retrospective analysis, the physical and/or electronic medical records (iMedOne, Deutsche Telekom AG; Bonn, Germany) of consenting patients were reviewed by A.O. and Dorit Schroeder to identify patients meeting eligibility criteria for inclusion. Data extracted from eligible patients included age, gender, smoking behavior, UC diagnosis (ie, ulcerative proctitis, left-sided colitis, or extensive colitis), current medications, fecal biomarker concentrations (FC and FL), and data for both histological indices (NI and RI).