Hemorrhagic Colitis Induced by Second-line Helicobacter pylori Eradication.

A 53-year-old man underwent esophagogastroduodenoscopy showing chronic gastritis with Helicobacter pylori (HP) infection. The first-line therapy for HP eradication failed, and the patient underwent second-line therapy comprising amoxicillin, metronidazole and vonoplazan. Three days after completing the treatment, he developed abdominal pain and hematochezia. Computed tomography showed thickening of the ascending colonic wall (Picture 1). Colonoscopy showed hemorrhagic and edematous mucosa in the ascending colon (Picture 2). A biopsy of the mucosa and stool culture provided no specific findings. The patient was diagnosed with antibiotic-associated hemorrhagic colitis (AAHC). He had a bowel rest and recovered. AAHC is a well-known complication of taking antibiotics and usually affects the ascending and transverse colon. Although several reports have suggested that antibiotic-induced overgrowth of Klebsiella oxytoca or allergic reaction can be associated with the development of AAHC, the definitive cause remains unknown (1). In Japan, the incidence rate of AAHC induced by first-line eradication therapy is reportedly 0.35-0.6% while the incidence rate with second-line eradication therapy is reportedly 0.96% (2). Clinicians should be aware of the possibility of AAHC after second-line therapy, even when no adverse events develop after first-line therapy.

Picture 1.

Picture 2.

The authors state that they have no Conflict of Interest (COI).