Background: Congenital Chloride Diarrhea (CCD) is a rare autosomal recessive condition characterized by lifelong watery diarrhea. CCD is challenging to diagnose because of its severe clinical presentations and differentials. Therefore, it is crucial to be diagnosed early and receive appropriate management as it causes early death if left untreated or due to complications. Case Report: A Saudi newborn baby boy who was passing a large amount of urine through the anal canal and was otherwise healthy. He was referred to our center with a high suspicion of a colovesical fistula. Diagnosed with CCD by exclusion of fistula after confirmation with contrast study. Conclusion: This case highlights an unusual presentation of CCD mimicking a colovesical fistula. To our knowledge, no similar case has been reported in the literature, and we believe this is the first Saudi case report. It underscored the diagnostic challenges of this rare disorder and emphasized the importance of early recognition and accurate diagnosis to prevent such complications.

Keywords: Congenital Chloride Diarrhea. Colovesical Fistula. Rare genetic. Autosomal Recessive. Pediatrics.