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炎症性腸疾患I:はじめに
炎症性腸疾患は、腸内細菌叢に対する異常な免疫反応により消化管の反発性炎症が特徴的な慢性疾患の一群です。これが組織の損傷を引き起こします。主な2つのタイプはクローン病と潰瘍性大腸炎です。
クローン病
クローン病は再発性炎症性疾患で、口から肛門まで消化管のあらゆる部分に影響を及ぼします。腸壁のすべての層(経…
炎症性腸疾患とは、異常な免疫反応によって引き起こされる消化管の再発性炎症を指します。
クローン病や潰瘍性大腸炎も含まれます。
クローン病は口から肛門まで消化管のあらゆる部位に影響を及ぼし、関与する特定の部位によって分類されます。これらは時折重複することもあります。
回腸炎は終末回腸と結腸に影響を与えます。
回腸炎は回腸に限られ、クローン病は結腸に限られます。
胃十二指腸疾患は胃と十二指腸に関わります。
空腸炎は回腸と空腸の両方に影響を及ぼし、肛門周囲の組織にも肛門周病が関与します。
潰瘍性大腸炎は、大腸および直腸の特発性炎症性疾患で、粘膜および粘膜下に限定されています。
通常は直腸から始まり、結腸を連続して近位に広がり、さまざまな提示パターンをとります。
直腸炎は直腸のみに影響し、直腸とS状結腸の両方に影響します。
左側大腸炎は脾屈曲にまで及び、膵炎は盲腸までの大腸全体に及びます。
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Q1: What is inflammatory bowel disease and what causes it?
Inflammatory bowel disease refers to recurrent inflammation of the gastrointestinal tract resulting from an abnormal immune response against gut microflora. This chronic disorder leads to tissue damage and includes two main forms: Crohn's disease and ulcerative colitis. Both conditions cause inflammation but differ in location and depth of involvement within the GI tract.
Q2: How does Crohn's disease differ from ulcerative colitis in terms of affected areas?
Crohn's disease can affect any part of the GI tract from the mouth to the anus and involves all bowel wall layers with skip lesions where diseased areas alternate with normal tissue. Ulcerative colitis is limited to the colon and rectum, affecting only the mucosa and submucosa, and spreads continuously from the rectum without skip lesions.
Q3: What are the different types of Crohn's disease based on location?
Crohn's disease is classified by affected areas: ileocolitis involves the terminal ileum and colon; ileitis is confined to the ileum; Crohn's colitis affects the colon; gastroduodenal disease involves the stomach and duodenum; jejunoileitis affects the jejunum and ileum; and perianal disease involves tissues around the anus.
Q4: What are the extent patterns of ulcerative colitis?
Ulcerative colitis presents in distinct patterns: proctitis affects only the rectum; proctosigmoiditis involves the rectum and sigmoid colon; left-sided colitis extends to the splenic flexure; and pancolitis involves the entire colon. Each pattern reflects progressive inflammation spreading continuously from the rectum.
Q5: What are the main symptoms associated with ileocolitis?
Ileocolitis, the most common form of Crohn's disease affecting the terminal ileum and colon, causes diarrhea, cramping, weight loss, and right lower abdominal pain. These symptoms result from inflammation in both the small and large intestines, making it the most frequently diagnosed Crohn's subtype.
Q6: How does pancolitis differ from other ulcerative colitis patterns in severity?
Pancolitis involves the entire colon and produces more severe symptoms than localized patterns, including profuse diarrhea, abdominal pain, and significant weight loss. Pancolitis also carries an increased risk of colon cancer compared to other ulcerative colitis extent patterns, making it the most serious presentation.
Q7: What complications can develop from perianal Crohn's disease?
Perianal disease, a form of Crohn's disease affecting tissues around the anus, can develop abscesses, fistulas, fissures, and skin tags. These complications result from transmural inflammation extending through all bowel wall layers to surrounding tissues, causing significant morbidity and requiring specialized management.