1例小肠血管畸形出血的粪便隐血检测方法差异启示

Enlightenment from Discrepancies in Fecal Occult Blood Test Methods in a Case of Small Intestinal Vascular Malformation Bleeding

摘要: 本文报告一例82岁女性患者，因反复黑便18年余，再发1天入院，既往确诊为小肠血管畸形。在诊疗过程中，粪便隐血检测出现免疫法(FIT)与化学法、转铁蛋白检测结果不一致的情况：免疫法呈阴性，而化学法及转铁蛋白检测呈阳性。该差异暴露出在血红蛋白受肠道环境影响降解时，单纯依赖免疫法可能漏诊持续出血。结合患者血红蛋白持续下降的临床表现，多方法联合检测纠正了单一方法的局限性，明确了出血未停止，指导临床继续止血治疗并调整监测策略。本案例提示，在不明原因消化道出血(OGIB)的评估中，应根据病情特点联合使用不同原理的隐血检测方法，以提高诊断准确性。

Abstract: This article reports the case of an 82-year-old female patient who was admitted to the hospital due to recurrent melena for over 18 years, with a recurrence one day prior. She had a previous diagnosis of small intestinal vascular malformation. During the diagnostic process, inconsistent results were observed among fecal occult blood tests: the immunochemical fecal occult blood test (FIT) was negative, while the chemical method and transferrin test were positive. This discrepancy highlighted that relying solely on the immunochemical method may lead to missed diagnoses of persistent bleeding when hemoglobin is degraded by the intestinal environment. Combined with the clinical manifestation of a continuous decline in the patient’s hemoglobin levels, the multi-method approach corrected the limitations of relying on a single method, confirming that the bleeding had not stopped and guiding the clinical decision to continue hemostatic treatment and adjust the monitoring strategy. This case suggests that in the evaluation of obscure gastrointestinal bleeding (OGIB), occult blood detection methods based on different principles should be used in combination according to the characteristics of the condition to improve diagnostic accuracy.