[A case of Edwardsiella tarda colitis, which proved challenging to distinguish from immune-related adverse events with nivolumab].

The patient, a man in his 80s, presented with diarrhea following one year of treatment for non-small cell lung cancer with Nivolumab. CT results showed discontinuous wall thickening of the large bowel and cholangitis. Blood and stool culture tests ruled out immune-related adverse events and identified Edwardsiella tarda;bacterial colitis was diagnosed in the patient. This case confirmed that basic examination should not be neglected, and culture tests should be performed.