便血

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Hematochezia
分类和外部资源
醫學專科英语Specialty (medicine) 胃肠学, 普通外科
ICD-9 578.1
DiseasesDB 19317

便血(英語:Hematochezia)是指新鲜血液通过肛门排除,通常是大便中带血(注意和黑便鉴别)。便血一般是和下消化道(即屈氏韧带以下的消化道)出血有关,但也可能因快速的上消化道出血而造成。

病因[编辑]

成年人便血最常见的原因是痔疮肠憩室病,这两个疾病相对是良性的。便血也可能是由于大肠癌引起,这个可能会致命。

在新生儿中,便血可能是因为在分娩时吞食了母体的血液而引起的,但也有可能是严重影响早产儿生命的坏死性小肠结肠炎的初始症状。

婴儿便血合并腹痛提示有肠套叠

青少年中便血一般是炎症性肠病引起,其中特别要注意考虑和排除溃疡性结肠炎,是一种引起便血的严重疾病。

便血也可由上消化道出血引起。然而,上消化道出血经常引起呕血,血液在沿着消化道向下流时会受到消化道酸和酶的化学作用,通常会表现为黑便。上消化道来源的便血是一个不祥的兆头,因为它预示这次出血非常显著快速,有可能会危及生命。

食用甜菜可能引起甜菜尿导致出现红色排泄物。这时由于一种红色素的代谢不足所导致,有时候可能会和便血混淆。

Causes[编辑]

In adults, most common causes are hemorrhoids and diverticulosis, both of which are relatively benign; however, it can also be caused by colorectal cancer, which is potentially fatal. In a newborn infant, haematochezia may be the result of swallowed maternal blood at the time of delivery, but can also be an initial symptom of necrotizing enterocolitis, a serious condition affecting premature infants. In babies, haematochezia in conjunction with abdominal pain is associated with intussusception. In adolescents and young adults, inflammatory bowel disease, particularly ulcerative colitis, is a serious cause of haematochezia that must be considered and excluded.

Haematochezia can be due to upper gastrointestinal bleeding. However, as the blood from such a bleed is usually chemically modified by action of acid and enzymes, it presents more commonly as black "tarry" feces known as melena. Haematochezia from an upper gastrointestinal source is an ominous sign, as it suggests a very significant bleed which is more likely to be life-threatening.

Beeturia can cause red colored feces after eating beets because of insufficient metabolism of a red pigment, and is a differential sign that may be mistaken as haematochezia.

Consumption of dragon fruit or pitaya may also cause red discoloration of the stool and sometimes the urine (pseudohematuria). This too, is a differential sign that is sometimes mistaken for hematochezia.

Reddish stool in toilet bowl water due to dragon fruit consumption

In infants, the Apt test can be used to distinguish fetal hemoglobin from maternal blood.

Other common causes of blood in the stool include:

相关条目[编辑]

参考资料[编辑]

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外部链接[编辑]