Efficacy and Safety of Retention Enema with Traditional Chinese Medicine for Chronic Radiation-Induced Rectal Injury: Study Protocol for a Multicenter Randomized Controlled Trial.

<p>Background: Chronic radiation-induced rectal injury (RRI) is a complication of pelvic radiotherapy, with existing treatments often providing suboptimal symptom relief. Traditional Chinese medicine (TCM) retention enema therapy, leveraging localized anti-inflammatory and mucosal regenerative properties, offers a promising alternative. This trial aims to evaluate the efficacy and safety of changrui enema powder (CEP), aiming to establish an evidence-based protocol for managing chronic RRI. Patients and Methods: This multicenter, randomized, triple-blinded controlled trial will enroll 180 participants (2:1 allocation) with grade 2 chronic RRI following pelvic radiotherapy. The experimental group will receive daily CEP enemas for 4 weeks plus a concurrent 1-week course of dexamethasone sodium phosphate (DEX) injection enemas, while the control group will receive an identical-appearing placebo enema for 4 weeks plus a concurrent 1-week course of DEX injection enema. Both interventions will be administered in a total enema volume of 100 mL. The primary outcome is the overall effective rate at 4 weeks, assessed using the LENT-SOMA scoring system. Secondary outcomes encompass TCM syndrome efficacy, the Vienna Rectoscopy Score, pain assessment, and quality of life. Conclusion: This trial is the first study to evaluate the efficacy and safety of a standardized TCM retention enema formulation (CEP) as an add-on to a short-course standard corticosteroid regimen for chronic RRI. The findings are expected to provide an objective clinical basis for integrating TCM into the management of chronic RRI and may inform the development of relevant clinical guidelines. </p>.