炎症性腸疾患の病変部位と鑑別診断—直腸病変

Diagnosis of Inflammatory Bowel Disease Using Rectal Lesions

要旨●直腸にはさまざまな病変があり，前処置薬なしで内視鏡観察可能であるが，反転観察しないと全体像が把握できない疾患もある．直腸のみに病変を認める疾患と直腸以外にも病変を認める疾患があり，後者では他部位の病変の性状により診断がつくことがある．直腸病変の診断では，患者背景，臨床症状，存在部位，潰瘍の形態・深さ・辺縁の性状などに注目する．炎症性腸疾患は，特徴的な画像所見があれば診断が容易であるが，慎重な経過観察で診断に至ることもある．確定診断の方法として病理組織検査，便培養などの細菌学的検査，抗原検査，抗体検査などがある．今回，炎症性腸疾患の直腸病変の臨床像，内視鏡像，鑑別疾患について述べる．

　The rectum can be observed with an endoscope without using pretreatment drugs to identify various lesions. However, in some diseases, diagnostic understanding cannot be obtained unless a rectal endoscopy is performed. Some diseases present lesions only in the rectum, whereas some present lesions in addition to those in the rectum. In the latter, diagnosis can be made depending on the features of the lesions at other sites. In the diagnosis of rectal lesions, considerations include the patient's background, clinical symptoms, ulcer site, morphology, depth, and type of ulcer edge. Inflammatory bowel disease is easy to diagnose from characteristic imaging findings, but if not, careful follow-up may lead to a diagnosis. Methods for definite diagnosis include histopathological tests and bacteriological tests such as stool culture, antigen tests, and antibody tests. This paper discusses the clinical picture, endoscopic imaging, and differential diagnosis of rectal lesions that are characteristic of inflammatory bowel disease.