Management of diarrhea in solid organ transplantation.

Diarrhea is a common complaint in solid organ transplant recipients. We review both infectious and noninfectious causes of diarrhea and their management. Diagnostics for diarrhea have now commonly incorporated multiplex gastrointestinal panels that provide rapid testing and identification of pathogens. The rate of Clostridium difficile in the transplant population has increased and fidaxomicin is now recommended as the therapy of choice for first episode and recurrences where available. Oral vancomycin remains an alternative. Norovirus is important to rule out in cases of chronic diarrhea. Nitazoxanide has shown mixed results when used as norovirus therapy. SARS-CoV-2, despite being a respiratory virus, can infect gut epithelium and present with diarrhea. Noninfectious causes especially mycophenolate-related as well as inflammatory bowel disease should be in the differential especially when no infectious cause has been identified. A detailed history, diagnostics including molecular testing and endoscopy, and targeted therapies for infectious causes are the mainstay for management of diarrhea in the transplant recipient.