The polymicrobial Actinomyces naeslundii and Pseudomonas aeruginosa sepsis in a patient with ulcerative colitis 2 months after colonoscopy.

We describe a case of an abrupt onset of polymicrobial Actinomyces naeslundii/Pseudomonas aeruginosa sepsis in a patient with a previously silent abdominal actinomycosis, developed 2 months after colonoscopy when the diagnosis of a left-sided ulcerative colitis was established. Prolonged high-dose ceftriaxone therapy was clinically effective, albeit accompanied by the development of a reversible pseudocholelithiasis that persisted for 5 months.