Abstract
As the antibiotic therapy progresses, the prevention and treatment of infectious diseases develop further. On the other hand, various side effects have been reported, especially the antibiotic-associated colitis is one of the most important cases for its rapid onset and clinical course. A case of Ampicillin-associated hemorrhagic colitis is reported. The patient was a 65 year-old man who was admitted to our hospital with lower bdaominal cramps and bloody diarrhea. Ampicillin administration, characteristic clinical course and colonofiberscopic findings made us possible to diagnose the case as Ampicillin-associated hemorrhagic colitis. The improvement of the symptoms and the disappearance of the mucosal lesion were observed immediately after the discontinuation of the drug. The patient was discharged on the 14th hospital day. Klebsiella oxytoca was detected from the stool culture in this case. Several cases with Klebsiella oxytoca were reported in Japan but not in other countries.
The hemorrhagic mucosal lesion is localized in the right side of the colon in most cases of antibiotic-associated colitis particularly in that of Ampicillin. However, in this case, the lesion was observed in the whole length of the colon. At present, the cause of pancolitis is not clear. It is assumed that the various host factors should be considered as a cause of the colitis other than factors, such as the direct drug effects on the bowel wall or effects of the altered bowel flora.
