A rare case of colorectal duplication with rectourethral fistula in a child: diagnostic challenges and surgical management from Northwest Ethiopia

BACKGROUND: Alimentary tract duplications are rare congenital anomalies. Colorectal duplication is particularly uncommon and may present with nonspecific features, posing diagnostic challenges. An association with rectourethral fistula is extremely rare. CASE PRESENTATION: A 2-year-old male child presented with chronic constipation, abdominal distension, failure to thrive, and recurrent urinary tract infections. The later development of pneumaturia and fecaluria suggested an enterourinary fistula. Contrast enema demonstrated a reversed rectosigmoid ratio without a clear transition zone, initially raising suspicion for Hirschsprung disease. Voiding cystourethrography confirmed a rectourethral fistula. Surgical exploration revealed a duplicated sigmoid colon and rectum. Due to diagnostic uncertainty and poor nutritional condition of the child, a staged surgical approach was undertaken. Initial surgery involved diverting sigmoid colostomy and rectal biopsy. Histopathology excluded Hirschsprung disease. Definitive surgery included excision of the duplicated colorectal segment, pull-through reconstruction, and fistula repair. The postoperative course was uneventful with marked improvement in nutritional status and bowel function. CONCLUSION: Colorectal duplication with rectourethral fistula is a rare condition that may present with overlapping features of other colorectal disorders. Careful clinical evaluation, appropriate imaging, and staged surgical management are essential for optimal outcomes, particularly in resource-limited settings.