直肠出血

定义

直肠出血 is when blood passes from the rectum or anus. Bleeding may be noted on the stool or be seen as blood on toilet paper or in the toilet. 血可能是鲜红色的. The term "hematochezia" is used to describe this finding.

选择的名字

直肠出血; Blood in the stool; Hematochezia; Lower gastrointestinal bleeding

注意事项

The color of the blood in the stools may indicate the source of bleeding.

黑色或柏油大便 may be due to bleeding in the upper part of the GI (gastrointestinal) tract, 比如食道, 胃, or the first part of the small intestine. In this case, blood is most often darker because it gets digested on its way through the GI tract. 不太常见, this type of bleeding can be brisk enough to present with bright red rectal bleeding.

Bleeding from the rectum may also be red or fresh. This usually means that the source of bleeding is the lower GI tract (colon and rectum).

Eating beets or foods with red food coloring can sometimes make stools appear reddish. In these cases, your doctor can test the stool with a chemical to rule out the presence of blood.

原因

直肠出血 causes include:

• 肛裂 (a cut or a tear in the anal lining, often caused by straining hard, hard stools or frequent 腹泻). It may cause sudden onset of rectal bleeding. There is most often pain at the anal opening.
• 痔疮, a common cause of bright red blood. They may or may not be painful.
• 直肠炎 (inflammation or swelling of the rectum and anus).
• 直肠脱垂 (rectum protrudes from the anus).
• 外伤或异物.
• 结直肠息肉.
• Colon, rectal, or anal cancer.
• 溃疡性结肠炎.
• 肠道感染.
• 憩室病 (abnormal pouches in the colon).

When to Contact a Medical Professional

Contact your health care provider if there is:

• 你的大便里有新鲜的血
• A change in the color of your stools
• Pain in the anal area while sitting or passing stools
• Incontinence or lack of control over passage of stools
• 不明原因的体重减轻
• Drop in blood pressure that causes dizziness or fainting

You should see your provider and have an exam, even if you think that hemorrhoids are causing the blood in your stool.

In children, a small amount of blood in the stool is most often not serious. The most common cause is constipation. You should still tell your child's provider if you notice this problem.

What to Expect at Your Office Visit

Your provider will take a medical history and perform a physical exam. The exam will focus on your abdomen and rectum.

You may be asked the following questions:

• Have you had any trauma to the abdomen or rectum?
• Have you had more than one episode of blood in your stool? 每个凳子都在这边吗?
• Have you lost any weight recently?
• Is there blood on the toilet paper only?
• 这凳子是什么颜色的?
• 问题是什么时候出现的?
• What other symptoms are present (abdominal pain, 吐血, 腹胀, 过多的气体, 腹泻, 或发热?

You may need to have one or more exams or tests to look for the cause:

• 直肠指诊.
• Anoscopy.
• 乙状结肠镜检查或 结肠镜检查 to look inside your colon using a camera at the end of a thin tube to find or treat the source of bleeding may be needed.
• 血管造影术.
• 出血扫描.

You may have one or more lab tests before, including:

• 全血细胞计数
• 血清化学
• 凝血的研究
• 凳子上的文化

参考文献

DeGeorge LM, Nable JV. 消化道出血. In: Walls RM，编辑. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10日艾德. Philadelphia, PA: Elsevier; 2023:chap 26.

黄志强，吴志强. Epidemiology, pathogenesis, and diagnosis of inflammatory bowel diseases. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11日艾德. Philadelphia, PA: Elsevier; 2021:chap 115.

Kwaan先生. 痔疮, anal fissure, and anorectal abscess and fistula. In: Kellerman RD, Rakel DP, eds. 康恩目前的治疗2022. Philadelphia, PA: Elsevier; 2022:219-222.

灯LW. 肛门. In: Goldblum JR, 灯LW, McKenney JK, Myers JL, eds. Rosai and Ackerman's Surgical Pathology. 11日艾德. Philadelphia, PA: Elsevier; 2018:chap 18.

斯沃茨MH. 腹部. 编辑:斯沃茨MH. Textbook of Physical Diagnosis: History and Examination. 8日艾德. Philadelphia, PA: Elsevier; 2021:chap 17.