Imdahl A
Department of Surgery, University Hospital of Freiburg, Hugstetterstrasse 55, 79106 Freiburg, Germany.
Langenbecks Arch Surg. 2001 Feb;386(1):1-7. doi: 10.1007/s004230000194.
The incidence of lower gastrointestinal bleeding (LGB) is estimated to be 20-30 per 100,000 of the adult population at risk, which is clearly correlated with increasing age. The problem of LGB is identification of the bleeding source. LGB stops spontaneously in 80% of cases, but 10% of bleeding sources cannot be identified, and rebleeding occurs in 25%. The quality of LGB--hematochezia, melena, or occult bleeding--may point to the region of the bleeding source, as patient age is correlated with specific pathologies. In many patients, LGB is a leading symptom of a chronic disorder. Most acute peranal bleeding arises from the colon (80%) with colonic diverticula and angiodysplastic lesions as the most frequent reasons. In 5% of cases, LGB is caused by disorders of the small bowel, in most cases due to small-bowel tumors or to Meckel's diverticulum in younger patients. In 15-20%, acute peranal bleeding is caused by lesions in the upper gastrointestinal tract. The intensity of LGB determines the urgency of identification of the bleeding source; however, chronic occult blood loss superimposed by melena may place the patient at risk as early as a patient with hematochezia. Therefore, prompt resuscitation is required in many LGB patients before diagnostic procedures are initiated.
据估计，下消化道出血（LGB）在每10万成年高危人群中的发病率为20 - 30例，这显然与年龄增长相关。LGB的问题在于确定出血源。80%的LGB病例可自行止血，但10%的出血源无法确定，且25%的病例会再次出血。LGB的表现形式——便血、黑便或隐匿性出血——可能指向出血源所在区域，因为患者年龄与特定病理情况相关。在许多患者中，LGB是一种慢性疾病的主要症状。大多数急性肛周出血源于结肠（80%），最常见的原因是结肠憩室和血管发育异常病变。5%的LGB病例由小肠疾病引起，在大多数情况下是由于小肠肿瘤或年轻患者的梅克尔憩室。15% - 20%的急性肛周出血由上消化道病变引起。LGB的严重程度决定了确定出血源的紧迫性；然而，慢性隐匿性失血叠加黑便可能使患者与便血患者一样早地面临风险。因此，在许多LGB患者开始诊断程序之前，需要进行及时的复苏。
