[Value of proctosigmoidoscopy with bacteriological culture of colonic biopsies in the etiological diagnosis of post-antibiotic acute diarrhea in adults. Prospective study in 24 patients].

The aim of this study was to analyse the interest of proctosigmoidoscopy and biopsies microbiology in antibiotic-associated acute diarrhea in adults. Between February 1993 and October 1995, we have studied prospectively 24 patients with antibiotic-associated acute diarrhea. Ages ranged from 17 to 83 years. They had taken antibiotics: amoxicillin (n = 8) amoxicillin-clavulanic acid (n = 11), cephalosporinia (n = 3), cotrimoxazole (n = 1), macrolide (n = 1). For each patient, 2 stool cultures with Cytotoxin assay for Clostridium difficile and 3 fecal samples for parasitic enteropathogens were collected. Proctosigmoidoscopy with biopsies microbiology was carried out in all patients. Stool culture was always negative but colonic biopsies cultures were positive with Klebsiella oxytoca in 7 patients. Cytotoxin assay of C. difficile was positive in 11 patients. Proctosigmoidoscopy permitted also diagnosis of 2 pseudomembranous colitis without cytotoxin assay of C. difficile. Proctosigmoidoscopy permitted diagnosis of 83% of antibiotic-associated acute diarrhea. Complementary to Cytotoxin assay of C. difficile, it should be necessary in antibiotic-associated acute diarrhea in adults.