炎症性腸疾患の診断基準と鑑別診断

Diagnostic Criteria and Differential Diagnosis of Inflammatory Bowel Disease

要旨●炎症性腸疾患（IBD）は潰瘍性大腸炎とCrohn病に大別され，いずれの疾患も特徴的な腸管病変を確認することがその診断に重要である．しかしながら，これらの所見はあくまでIBDの基準的所見であり，内視鏡所見のみでIBDの診断を確定することは困難である．IBD診断の原則は除外診断であり，IBDの確定診断で最も重要なことは類似の症状や腸管病変を呈する他の疾患を除外することである．それゆえ，このような疾患の特徴を理解することはIBDと多岐にわたる消化管の炎症性疾患を鑑別するうえで有用である．本稿では，IBDの診断手順と鑑別診断のポイントについて概説する．

　Identifying the characteristic involvement of the gastrointestinal tract is important for diagnosing inflammatory bowel disease（IBD）, including ulcerative colitis and Crohn's disease. However, these findings are only indicative of IBD, and making a definite diagnosis of IBD by relying only on endoscopic findings can be challenging for physicians. The most important aspect for definite diagnosis of IBD is to exclude other diseases that show similar symptoms and bowel involvement. Therefore, a comprehensive understanding of the unique characteristics of a wide variety of inflammatory conditions of the gastrointestinal tract has proven useful for their accurate diagnosis. In this article, we review the diagnostic strategies for IBD as well as discuss its key features to improve its differential diagnosis.