What is Crohn's disease? A Mayo Clinic expert explains

Learn more about Crohn's disease from gastroenterologist William Faubion, M.D.

I'm Dr. Bill Faubion, a gastroenterologist at Mayo Clinic. In this video, we'll cover the basics of Crohn's disease. What it is? Who gets it? The symptoms, diagnosis and treatment. Whether you're looking for answers for yourself or someone you love, we're here to give you the best information available. Crohn's disease is an inflammatory bowel disease that causes chronic inflammation of the GI tract, which extends from your stomach all the way down to your anus. Different areas of the GI tract can be affected in different people, and it often spreads into the deeper layers of the bowel. It's estimated that over half a million Americans are living with Crohn's disease. It can be painful and debilitating, occasionally leading to severe complications, as well as emotionally stressful. And while there is no cure, once you've been diagnosed, treatment can help you get back to a more normal and comfortable life.

There are a lot of particulars that figure into or aggravate Crohn's disease, but the exact cause is still unknown. It may involve an abnormal immune response against some microorganism in which your tissues are also attacked. Genetics might also play a role. And it's true that you're at higher risk if a first-degree relative has it. But that's really only seen in about 20% of cases. There is a correlation with age. Although it can show up at any stage of life, most people are diagnosed before 30. Ethnicity is a risk factor. Whites have the highest risk, especially among people of Ashkenazi Jewish descent. However, incidence is increasing among black people in North America and the UK. Non-steroidal anti-inflammatory medications or NSAIDS... they don't cause Crohn's disease, but they are known to trigger inflammation of the bowel and make it worse. They include common over-the-counter painkillers like ibuprofen, naproxen sodium, diclofenac sodium, and others. So if you've been diagnosed with Crohn's, make sure you talk to your doctor about what medications should be avoided. Many of these elements are out of our hands, but smoking is the most important controllable risk factor for developing Crohn's disease. It also leads to more severe disease and increased need for surgery. So if you smoke and you're diagnosed, now is a good time to quit.

Crohn's disease can affect any area in the GI tract, but it's mostly found in the large and the small intestine. It can also be confined to one area or found in multiple segments. Symptoms can range in severity and it can depend on the area of the GI tract that's affected. You also may experience periods of remission when you have no symptoms or issues at all. The symptoms can come on gradually, but they can also show up suddenly. And these can include diarrhea, fever, fatigue, abdominal pain and cramping, blood in your stool, mouth sores, reduced appetite and weight loss. If your Crohn's disease has caused fistulas or inflamed tunnels in the skin near the anal area, you may notice pain or drainage. And in more severe cases, you may have inflammation of the eyes, skin, joints, liver or bile ducts, kidney stones, and anemia. In children, it can delay growth and development. Over time, Crohn's disease can lead to other complications, including bowel obstruction, ulcers, fistulas, anal fissures, malnutrition, and other health problems. It can also increase your risk for blood clots and colon cancer. Having these symptoms doesn't automatically mean you have Crohn's. But if you're experiencing anything that concerns you, it's a good idea to make an appointment with your doctor.

There's no single test for Crohn's disease, and it has similar symptoms to a lot of other conditions, so it can take a little time to get a diagnosis. First, your doctor is going to consider your medical history. Then your doctor may want to run a variety of tests or procedures. And at some point, your general practitioner may want to refer you to a specialist called a gastroenterologist like myself. A blood test can check for anemia and check for signs of infection. A stool study can test if there's blood present or rule out certain pathogens. A colonoscopy may be needed. This also allows your doctor to view your entire colon and the very end of the ileum using an endoscope, a small camera mounted on a thin flexible tube. They can take tissue samples for a biopsy at the same time. And the presence of granulomas or clusters of inflammatory cells can essentially confirm the diagnosis. A CT scan might be ordered for a better look at the bowel and all of the surrounding tissues; or an MRI, which is especially good for evaluating fistulas around the anus or the small intestine. A capsule endoscopy can be done. Here you actually swallow the camera about the size of a large vitamin and it takes images of your digestive tract as it travels through. And a balloon- assisted enteroscopy may be done to get further into the bowel than a standard endoscope can if abnormalities have been found that need further investigation.

Your doctor can work with you to find therapies that alleviate your symptoms. One of the main goals is to reduce the inflammation that produces painful and disruptive issues. Another is to limit complications over the long-term. There is currently no cure, but many treatments can provide a lot of relief, and in some cases, even long-term remission. These may include anti-inflammatory drugs like corticosteroids, immune system suppressants, and antibiotics. Certain biologics, which target proteins made by the immune system, can help. Antidiarrheals, pain relievers, and supplements can help counter other symptoms. Nutritional therapy and a special diet may be recommended. And in some cases where other measures aren't effective, surgery may be required. And that's to remove the damaged tissue. Some of these therapies may have side effects themselves. So be sure and review the risks and benefits with your doctor.

Crohn's disease can be physically and emotionally challenging, but there are things that can help. Although there's no firm evidence that any particular foods cause Crohn's disease, certain things seem to aggravate flare-ups. So a food diary can help you identify personal triggers. Beyond that, limit dairy products, eating smaller meals, stay hydrated, and try to avoid caffeine, alcohol, and carbonation. Consider multivitamins if you're concerned about weight loss. Or if your diet has become too limited, talk to a registered dietitian. And again, if you smoke, you should stop. It's important to take care of your mental health too. Find ways to manage stress, like exercise, breathing, relaxation techniques or biofeedback. Some symptoms like abdominal pain, gas, and diarrhea... they can cause anxiety and frustration. They can make it difficult to go out in public for any amount of time. It can feel limiting and isolating and lead to depression. So learn as much as you can about Crohn's. Staying informed can help a lot in feeling like you're in control of your condition. Talk to a therapist, especially one familiar with inflammatory bowel disease. Your doctor can give you some recommendations. And you might want to find a support group of people going through the same thing that you are. Crohn's disease is a complex disease. But having expert medical care and developing a treatment strategy can make it more manageable and even help you get back to the freedom of your normal life. Meanwhile, significant advances continue to be made in understanding and treating the disease, getting us closer to curing it or preventing it entirely. If you'd like to learn more about Crohn's disease, here are other related videos or visit mayoclinic.org. We wish you well.











  • 腹泻
  • 发热
  • 疲劳
  • 腹痛和痉挛
  • 便血
  • 口腔溃疡
  • 食欲不佳和体重减轻
  • 因皮下腔道(瘘管)发炎而导致肛门附近或周边疼痛或排液



  • 皮肤、眼睛和关节炎症
  • 肝脏或胆管炎症
  • 肾结石
  • 缺铁性贫血
  • 儿童生长或性发育迟缓



  • 腹痛
  • 便血
  • 恶心和呕吐
  • 非处方药 (OTC) 对其无效的持续性腹泻
  • 持续一两天以上的不明原因发热
  • 不明原因的体重减轻

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  • 免疫系统。病毒或细菌可能诱发克罗恩病。然而,科学家尚未确定这种诱因。当您的免疫系统尝试战胜正入侵的微生物时,免疫应答异常也导致免疫系统攻击消化道细胞。
  • 遗传。克罗恩病在拥有患病家庭成员的人群中更常见,因此基因可能在使人们更易感方面发挥作用。但是,大多数克罗恩病患者没有此病的家族史。



  • 年龄。任何年龄段都可能得克罗恩病,但年轻时更容易得这个病。多数患有克罗恩病的人是在 30 岁以前被诊断出来的。
  • 种族。虽然克罗恩病会影响任何种族,但白人风险最高,特别是东欧犹太人(阿什肯纳兹犹太人)后裔。然而,生活在北美和英国的黑人患克罗恩病的几率在上升。
  • 家族史。如果您的父母、兄弟姐妹或孩子等直系亲属患有该病,则您的患病风险更高。多达1/5的克罗恩病患者,其家庭成员患有该病。
  • 抽烟。抽烟是患克罗恩病最重要的可控风险因素。抽烟也会导致该病加重,增加手术的风险。如果您抽烟,请务必戒烟。
  • 非甾体抗炎药。这些药物包括布洛芬(Advi、Motrin IB 等)、萘普生 (Aleve)、双氯芬酸钠等。这些药物虽然不会导致克罗恩病,但会造成肠道炎症,使克罗恩病恶化。



  • 肠梗阻。克罗恩病可能影响肠壁的整体厚度。随着时间的推移,肠道的一些部分可能结疤和变窄,这可能阻碍消化道内容物的流动。您可能需要通过手术切除肠道的病变部分。
  • 溃疡。慢性炎症可能导致消化道的任意部位(包括口腔和肛门)以及生殖器区域(会阴)出现开放性疮疡(溃疡)。
  • 瘘管。溃疡有时会穿透肠壁,形成瘘管(不同的身体部位之间的异常连接)。瘘管可能出现在小肠与皮肤之间,或者出现在小肠与另一个器官之间。位于肛门区域附近或周围(肛周)的瘘管是最常见的一种瘘管。



  • 肛裂。这是肛门衬膜组织或肛门周围皮肤上的一个小裂口,可能发生感染。它通常与排便疼痛有关,并可能导致肛周瘘。
  • 营养不良。腹泻、腹痛和痉挛可能导致您难以进食,或者导致您的小肠难以吸收足够的营养。由于这种疾病会导致铁或维生素 B-12 含量低,因此经常出现贫血。
  • 结肠癌。患有影响结肠的克罗恩病会增加患结肠癌的风险。对于未患克罗恩病的人而言,一般结肠癌筛查准则要求从 50 岁开始,每 10 年接受一次结肠镜检查。请咨询医生您是否需要更早、更频繁地接受这项检测。
  • 其他健康问题。克罗恩病可能导致身体的其他部位出现问题。这些问题包括贫血、皮肤病、骨质疏松症、关节炎以及胆囊或肝脏疾病。
  • 药物风险。有些治疗克罗恩病的药物通过阻断免疫系统的功能来发挥作用,它们会略有导致淋巴瘤和皮肤癌等癌症的风险。它们还会增加感染的风险。


  • 血凝块。克罗恩病会增加静脉和动脉中出现血凝块的风险。

在 Mayo Clinic 治疗

Jan. 13, 2022
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