佛山市第一人民医院于2025年2月收治1例59岁女性患者，以血便、下腹痛为主要表现，肠镜检查发现直肠溃疡，病理提示急性炎症，初诊为溃疡性直肠炎。经规范抗炎治疗1个月，症状无改善。最终通过粪便镜检联合消化道病原体靶向高通量测序（tNGS）确诊为溶组织内阿米巴直肠炎。确诊后，予抗阿米巴治疗（口服甲硝唑片，0.2 g/次，3次/d），患者下腹痛显著缓解，血便逐渐消失。治疗2周后复查，临床症状消失，粪便潜血阴性，粪便镜检未检出阿米巴滋养体或包囊，tNGS未检出溶组织内阿米巴特异性基因序列。本案例揭示了溶组织内阿米巴肠炎诊断面临症状不典型，电子肠镜及病理表现缺乏特异性、传统病原学检测方法敏感性不足等多重挑战。对治疗无效的肠道溃疡患者，应积极采用分子检测技术以提高诊断准确性，避免误诊误治。

This article reports a case of a 59-year-old female patient presenting with hematochezia and lower abdominal pain. Colonoscopy revealed rectal ulcers, and histopathology showed acute inflammation, leading to an initial diagnosis of ulcerative proctitis. After one month of standard anti-inflammatory therapy without clinical improvement, the diagnosis was revised to amoebic proctitis through stool microscopy combined with targeted next-generation sequencing (tNGS). The patient showed rapid symptomatic relief following anti-amebic treatment. This case highlights the diagnostic challenges of Entamoeba histolytica proctitis, including nonspecific clinical manifestations, endoscopic and pathological findings lacking specificity, and the limited sensitivity of conventional pathogen detection methods. For patients with treatment-refractory intestinal ulcers, molecular diagnostic techniques should be actively employed to improve diagnostic accuracy and prevent misdiagnosis and inappropriate treatment.