[Diarrhea induced by antibiotics]

The most frequent cause of antibiotic-associated colitis is Clostridium difficile. This gram-positive, spore-forming anaerobic bacillus releases toxins, which produce diarrhea and damage the colonic mucosa. Endoscopy shows a wide range of alterations, "unspecific colitis" with reddening or edema, ulcerations or at the worst pseudomembranous colitis. Nearly all antibiotics are able to trigger Clostridium difficile colitis. An enhanced risk is exerted by broad spectrum substances, which act also on the anaerobic flora protecting the gastrointestinal tract from unphysiological colonization. Clusters of cases were observed in hospitalized patients. The patients risk factors coincide with the administration of antibiotics. Furthermore Clostridium difficile is likely to be spread as a nosocomial infection in many instances. Less often colitis is observed in connection with oral antibiotics outside the hospital. However, substantial underreporting of cases has to be considered. Clinical symptoms usually start 4 to 10 days after first administration of the antibiotic. Leading symptoms are frequent profuse watery stools. Abdominal cramps and tenderness as well as fever and leukocytosis are common. Intense symptoms can simulate serious conditions like perforation. Upon clinical suspicion the diagnosis is made by endoscopy, stool culture and possibly demonstration of toxin. The predictive value of the stool culture equals that of toxin detection. In adult patients there is a good correlation between positive stool culture and clinical presentation. Infants can carry Clostridium difficile as part of their normal flora, therefore positive stool culture or toxin detection in an infant cannot necessarily be linked to clinical symptoms. In some cases Clostridium difficile has to be regarded as etiologic organism also in infants.(ABSTRACT TRUNCATED AT 250 WORDS)