Abstract
Three patients with an acute colitis in which the only pathogen detected was either Aeromonas hydrophila or A sobria progressed to a chronic phase after the infection had been eliminated by antibiotic treatment in two and had resolved spontaneously in the third. The final diagnosis in each case was ulcerative colitis. Two of the patients have responded to anti-inflammatory medication but one has required panproctocolectomy. The sequence of symptoms and observations in these cases, as well as in others from the literature involving more familiar pathogens, suggests that bacterial infection may contribute to the development of chronic colitis. This supposition could be tested by extending the follow up of patients with acute infective colitis in a prospective multicentre trial.