8．感染性大腸炎の鑑別診断―感染性大腸炎間の鑑別と薬剤性腸炎との鑑別

Differential Diagnosis of Infectious Disease: Distinction Between Various Infectious Diseases and Distinction from Various Drug Induced Colitis

要旨　感染性腸炎の診断過程には，多くの疾患の鑑別が必要である．感染性腸炎同士の鑑別あるいは薬剤性腸炎を含む炎症性疾患を除外する必要がある．感染性腸疾患の診断の第一歩には毒素性細菌感染と組織侵入性感染を区別し，その後，後者の鑑別を進める．また古典的感染症と薬剤性腸炎に加え，最近増加傾向にある腸管出血性大腸菌感染とNSAIDs起因性大腸炎も鑑別すべきである．感染性腸炎と薬剤性腸炎は，臨床像や内視鏡像が共通することも多い．また，細菌学的検索が行われても両者を鑑別できないことも少なくないなどの問題点がある．上記の多数の疾患を鑑別する要点を総説的にべた．

　Clinical and endoscopic diagnosis of infectious colitis necessarily involves the process of differentiation of various diseases. Differentiation between infectious diseases and various drug-induced colitis is mandatory before there can be a final diagnosis of an infectious disease. Distinction of toxin-producing bacterial infections is the first step and differentiation between tissueinvading infectious organisms is the second step. Newly recognized infectious diseases and drug induced colitis such as enterohemorrhagic E. coli infection and NSAIDs induced colitis have to be considered in the process of disease distinction. However, endoscopic differentiation is often difficult because of common features between infectious and drug-induced colitis. In the routine diagnostic process, one of the most important problems is frequent uncontributory bacteriological examination which make differentiations difficult. In this review, the diagnositic issue in endoscopic examination of infectious diseases is discussed in contrast with the diagnosis of mainly drug-induced colitis.