Acute segmental hemorrhagic antibiotic-associated colitis

Three cases of acute segmental hemorrhagic antibiotic-associated colitis are described occurring in three male adults between 30 and 33 years of age after treatment with oral ampicillin or amoxicillin because of upper respiratory tract infection, tonsillitis, or HLO eradication therapy, respectively. All presented with cramping abdominal pain and bloody diarrhoea of acute onset, however, microbial analysis of fecal samples was negative. Endoscopy showed right-sided segmental hemorrhagic colitis. Histopathological examination demonstrated edema, patchy superficial hemorrhage and a scattered predominantly mononuclear infiltrate of the lamina propria. The surface epithelium was partly desquamated and displayed foci of grouped intraepithelial red blood cells. All patients spontaneously recovered after discontinuation of antimicrobial therapy. The value and limitations of diagnostic features are discussed with respect of the literature.