Introduction: Isolated proctitis (IP), or ulcerative proctitis, a subtype of ulcerative colitis (UC), is associated with distressing symptoms such as frequent stools, rectal bleeding and bowel urgency. As patients with IP not responding to conventional treatment are understudied and underrepresented in clinical trials, treatment guidance is limited. We aimed to understand disease burden among IP patients by describing patients delineated by disease extension and treatment experience.

Methods: Data were drawn from the Adelphi UC Disease Specific Programme™, a cross-sectional survey of gastroenterologists (GIs) and their consulting patients in France, Germany, Italy, Spain, the United Kingdom and the United States from October 2020-March 2021. GIs reported patient demographics, disease extension, symptoms, components of the full Mayo score (allowing total scores to be calculated for patients), and treatment profile at time of consultation. Patients with a history of physician-assessed moderate-severe disease were included. Patients were categorized as IP (IP at diagnosis and consultation) or as more extensive UC (MEUC; where disease extended beyond IP at both diagnosis and consultation). According to ECCO consensus guidelines¹, patients are considered refractory if they have failed oral steroids combined with oral and rectal 5-ASA therapy. In this analysis, non-refractory IP patients had only received 5-ASAs and/or steroids; refractory IP patients had received an immunomodulator (IM) and/or advanced therapy (AT; biologics, Janus kinase inhibitors). All analysis were descriptive.

Results: Overall, 221 IP patients (118 non-refractory, 103 refractory) and 1,607 MEUC were analyzed. Among IP, non-refractory IP, refractory IP, and MEUC 49.3%, 55.1%, 42.7%, and 55.4% were male, respectively, and mean age ranged 39.0-40.2 years. Symptoms most reported by IP, non-refractory IP, refractory IP, and MEUC patients were abdominal pain (33.8%, 26.5%, 41.7%, 26.0%), fatigue/tiredness (22.7%, 20.4%, 25.2%, 23.8%) and bowel urgency (22.7%, 25.7%, 19.4%, 23.6%). According to Mayo scores at consultation, 40.3% of IP, 44.9% of non-refractory IP, 34.9% of refractory IP, and 50.4% of MEUC patients were in remission. Since diagnosis, 33.5% of IP, 71.8% of refractory IP, and 69.1% of MEUC cohorts had received AT.

Conclusions: Patients with IP experience a similar symptom burden to the MEUC population, despite currently available treatments for UC. The high AT use and low rate of remission indicates undertreatment of IP patients and a need for therapies with proven efficacy in this population, particularly after conventional therapy use.