Factors associated with mesalamine refractory ulcerative proctitis requiring advanced medical treatments

Ulcerative proctitis (UP) is a subtype of ulcerative colitis (UC) affecting the rectum, usually manageable with mesalamine. However, a subgroup of patients is refractory to mesalamine, necessitating advanced therapies. We aimed to assess risk factors for refractory disease.

Data on proctitis patients were collected retrospectively from a single tertiary center during 2010-2024. Proctitis was defined as maximal disease extent of 20 cm from the anal verge. Patients treated with immunomodulators and/or biological therapy were considered to have refractory proctitis. Multivariable logistic regression analysis was used to identify risk factors.

We included 230 patients in the analysis, of whom 50 (21.7%) patients had refractory disease. At diagnosis, refractory patients were younger (25.0 years [20.0-32.0] vs. 30.5 years [22.5-41.0], p = 0.008), had longer disease extent (12.37 cm ± 5.81 vs. 9.87 cm ± 5.40, p = 0.018), had more severe endoscopic activity (Mayo endoscopic score [MES] 2/3: 21 [87.5%] vs. 45 [59.2%], p = 0.025) and more often used rectal steroids (24 [48.9%] vs. 31 [17.3%], p = 0.009). There was no difference between groups in sex, BMI, smoking status, presence of cecal patch, use of rectal 5-ASA or follow-up duration. In the multivariable regression model, the only significant predictors were use of topical steroids (odds ratio 4.0, 95% CI 1.13-14.13, p = 0.031) and baseline endoscopic severity (odds ratio 5.23, 95% CI 1.04-26.27, p = 0.044).

The use of topical steroids and endoscopic disease severity at diagnosis were associated with refractory proctitis. These results may help stratify patients who could benefit from closer, tailored monitoring strategies.