Radiation-Induced Proctitis and Hemorrhagic Cystitis: A Review of Management With Comparative Perspectives on Radiation Enteritis and Pneumonitis.

Radiation therapy is a cornerstone in the management of pelvic and thoracic malignancies, but injury to surrounding normal tissue remains a clinically significant source of late morbidity despite advances in treatment delivery. Radiation-induced proctitis and hemorrhagic cystitis are consequential pelvic toxicities, typically presenting months to years after treatment with rectal bleeding, diarrhea, urgency, tenesmus, hematuria, and irritative lower urinary tract symptoms. Beyond the pelvis, radiation enteritis and pneumonitis represent important gastrointestinal and pulmonary complications that may similarly impair quality of life. Although severe toxicity has become less common with contemporary treatment planning, management remains challenging because of the chronic, multifactorial nature of radiation injury and limited high-quality randomized evidence. Treatment is generally individualized according to symptom severity, affected organ, and chronicity. Medical therapies include anti-inflammatory agents, antioxidants, and topical or intravesical treatments aimed at reducing inflammation and promoting mucosal healing. For chronic hemorrhagic disease, endoscopic interventions such as argon plasma coagulation, radiofrequency ablation, laser therapy, and cryotherapy target friable or telangiectatic lesions. In refractory cases, hyperbaric oxygen therapy (HBOT) has emerged as an important salvage modality by promoting angiogenesis, neovascularization, and tissue repair in irradiated tissue. Surgery is reserved for severe, refractory disease or complications, including fistula, obstruction, or life-threatening hemorrhage. This review examines contemporary management of radiation-induced proctitis and hemorrhagic cystitis, with comparative discussion of radiation enteritis and pneumonitis. We highlight organ-specific differences in pathophysiology, presentation, medical and endoscopic therapies, HBOT, and surgical intervention, emphasizing a stepwise approach to management.