16.感染性腸炎

Infectious Enterocolitis

要旨　下痢を伴う血便患者に遭遇した場合，感染性腸炎も念頭に置き，病歴の聴取，細菌学的検査を行う．鑑別診断上速やかに大腸内視鏡検査がなされるので感染性腸炎の内視鏡所見を熟知しておく必要がある．特徴的所見は，カンピロバクター腸炎におけるBauhin弁上潰瘍，腸炎ビブリオ腸炎においては大腸に所見が乏しくBauhin弁の腫大と終末回腸のびらん，腸管出血性大腸菌腸炎における右側結腸ほど高度の所見を示す縦走ないし全周性潰瘍などであるが，しばしばみられる左側結腸の縦走潰瘍は虚血性大腸炎との，散在性ないしアフタ性びらんは他の感染性腸炎との鑑別を要する．アメーバ赤痢ではタコイボ状びらんなど特徴的所見に加え生検組織診断も有用である．

　We take medical histories and make microbiological examination when we suspect infectious enterocolitis in patients with complaints of diarrhea and hematochezia.

　As urgent colonoscopy is performed in the examination, it is important to know the colonoscopic findings of infectious enterocolitis. Characteristic findings are ; 1) Ulcer on Bauhin's valve in Campylobacter enterocolitis ; 2) Swelling on Bauhin's valve and erosion in the terminal ileum in Vibrio parahaemolyticus enterocolitis ; 3) Longitudinal or diffuse ulcer seen to a high degree on the right side colon in Enterohemorrhagic Escherichia coli (O157 : H7) enterocolitis. Longitudinal ulcer on the left side colon and scattered erosion or aphthoid erosion are seen in various kinds of infectious enterocolitis. Awareness of these characteristics are necessary to differentiate infectious enterocolitis from ischemic colitis and other types of enterocolitis. In amoebic colitis characteristic findings of takoibo erosion and detection of Entamoeba histolytica from biopsy specimens are useful for diagnosis.