Comparing TRIple Rectal Ultrasound Imaging Technology in Ulcerative Colitis

This study aims to evaluate the correlation of rectal wall thickness and vascularity measurements using trans-abdominal ultrasound (TAS), trans-perineal ultrasound (TPUS), and endoscopic ultrasound (EUS) in adult patients with ulcerative colitis (UC). The primary objective is to correlate rectal total wall thickness measured by TPUS with EUS, while secondary objectives include correlating rectal wall thickness and vascularity as measured by TAS, TPUS, and EUS, with endoscopic and histologic activity. Additionally, the study will assess changes in patient management following EUS/sigmoidoscopy compared to TAS/TPUS alone. Consecutive UC patients attending an IBD clinic will undergo clinical assessment using the Simple Clinical Colitis Activity Index (SCCAI) followed by TAS and TPUS as point-of-care tests. If clinically indicated, patients will also undergo sigmoidoscopy and EUS during the same visit, with measurements compared and correlated to histologic inflammation and fecal calprotectin (FCP) levels when available. This cross-sectional study will include a follow-up period until biopsy results are obtained, with a recruitment duration of 6-12 months and a target sample size of 170 patients (60 patients with mid-end ultrasound machine, rest with high-end ultrasound machine for transabdominal and transperineal ultrasound).