15.潰瘍性大腸炎

Ulcerative Colitis

要旨　潰瘍性大腸炎は血便を来す疾患の中で最も一般的であり，経過中血便を呈さない潰瘍性大腸炎はないと言っても過言ではない．慢性の粘血便や下痢を主症状とするが，診断は生検を加味しても除外診断であり，特に感染性腸炎との鑑別が必要で，初診時には便培養が必須である．活動期の内視鏡検査は前処置なしで慎重に行い，決して無理はしない．注腸X線検査は希釈したバリウムにprednisoloneを混入して行う．潰瘍性大腸炎の経過中に下血を来したときには，再燃のほかに，高齢者では虚血性変化による縦走潰瘍の合併を，治療中に高熱を伴う下血をみたときにはサイトメガロウイルス感染の合併も考慮する．10年以上の長期経過例で下血をみるときには癌の合併も念頭に置き検査を進める．また，外科手術後の下血をみるときには，回腸嚢炎の存在も念頭に置く．このように，潰瘍性大腸炎患者における血便・下血をみるときには，患者の年齢，病状等を考慮しながら鑑別診断を行うことが重要である．

　Ulcerative colitis is one of the most common colorectal diseases which presents hematochezia (bright red blood per rectum : BRBPR). It is exaggeration to say that during the course of ulcerative colitis hematochezia is always presented. The common chief complaints of ulcerative colitis are chronic mucous bloody stool and diarrhea, and a definitive diagnosis can be made after exclusion of other diseases because endoscopic and histologic findings are non-specific. It is very important that infectious colitis be excluded by stool culture, especially in the initial diagnosis of ulcerative colitis. Colonoscopy for active ulcerative colitis should be cautiously and reasonably carried out even without preparation. Barium enema study should be performed, using diluted barium containing some prednisolone. When hamtochezia is presented during the progress of the disease, disease relapse should be considered firstly and several other conditions also have to be considered. When hematochezia and abdominal cramp are presented in elderly patients, longitudinal ulcers caused by ischemic change should be considered. When hematochezia and high fever are presented during remission induction therapy, concomitant cytomegalovirus colitis should be considered as a possible cause. When hematochezia is presented in long-standing ulcerative colitis patients of more than 10 years, colitic cancer should be considered. When it is presented in patients after surgery, pouchitis should be considered. When hematochezia is presented in patients with ulcerative colitis, the age of the patient or the condition of the disease should be considered in order to reach a precise diagnosis.