背景：直肠脱垂是直肠通过肛门的圆周、全层突出，如果处理不当，可能会被嵌顿并造成勒死的风险。除非遇到并发症，否则这种病理很少是医疗紧急情况。这些并发症包括感染、坏死、穿孔、嵌顿和不受控制的疼痛。病例介绍：我们报告一例患有慢性直肠脱垂相关疼痛的老年患者。手术干预已被排除，并且使用全身镇痛药后疼痛也没有缓解。病例管理：根据越来越多的镇痛特性报告，在脱垂器官外用局部亚甲蓝（MB）0.1%，可缓解疼痛。病例结果：患者的疼痛得到立即且持久的缓解；根据需要每 12 小时继续进行一次 MB 应用。经过这种治疗后，患者不再需要全身镇痛药。没有副作用的报道。结论：局部 MB 可能是治疗慢性直肠脱垂相关疼痛的有效镇痛药。这种治疗方法可能会推广到其他外皮疼痛的临床情况。类似的用途已被证明在其他病症中是安全有效的，包括与癌症治疗相关的口腔粘膜炎疼痛。

Background: Rectal prolapse is a circumferential, full-thickness protrusion of the rectum through the anus, which, if not properly managed, may become incarcerated and pose a risk of strangulation. This pathology is rarely a medical emergency unless a complication is encountered. Such complications include infection, necrosis, perforation, incarceration, and uncontrolled pain. Case Presentation: We report a case of an elderly patient with pain associated with chronic rectal prolapse. Surgical intervention had been ruled out, and there had been no pain relief after using systemic analgesics. Case Management: Based on increasing reports of analgesic properties, topical methylene blue (MB) 0.1% was applied externally at the prolapsed organ, obtaining pain relief. Case Outcome: The patient experienced immediate and long-lasting pain relief; MB applications were continued every 12 hours as needed. After this therapy, the patient was no longer in need of systemic analgesics. No side effects were reported. Conclusion: Topical MB may be an effective analgesic for the management of pain associated with chronic rectal prolapse. This treatment might be extrapolated to other clinical scenarios of tegumentary pain. Similar use has been shown to be safe and effective in other pathologies, including pain in oral mucositis associated with cancer therapy.