Cord colitis syndrome is a diarrheal illness in recipients of umbilical cord blood transplant. It causes a granulomatous inflammation of the upper and lower gastrointestinal tract and responds to antimicrobial treatment including metronidazole.[1] It was first described in 2011.[2] In 2013, a sequencing study identified a newly discovered bacterium, called Bradyrhizobium enterica, in biopsy samples from two patients. That this bacterium is responsible for this syndrome can be suggested, but not yet confirmed.[3] Subsequent studies showing that Bradyrhizobium species are common contaminants of laboratory kit reagents have thrown this connection into doubt.[4]