An uncommon case of hematochezia.

Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder, primarily associated with mutations in the SMAD4 and BMPR1A genes[1]. It is characterized by the development of multiple juvenile polyps throughout the gastrointestinal tract, most commonly located in the rectum and sigmoid colon. Cases of JPS with ossification are exceedingly uncommon, and the underlying pathogenesis remains unclearly. Several mechanisms have been implicated in ectopic ossification, including sensory neuron activation, lymphocytic infiltration, mast cell degranulation, skeletal muscle cell necrosis, and endothelial-to-mesenchymal transition.The presence of ossification may indicate an increased risk of disease progression, underscoring the importance of regular endoscopic surveillance in affected patients.