Stage 1 necrotizing enterocolitis in newborn

This code represents the initial, mildest stage of necrotizing enterocolitis (NEC) in a newborn, characterized by non-specific signs such as lethargy, temperature instability, apnea, bradycardia, and abdominal distension, but without definitive radiographic evidence of pneumatosis intestinalis or portal venous gas. It indicates suspected NEC where clinical symptoms are present, but the disease has not progressed to more severe stages.

Use this code when a neonate presents with early clinical signs suggestive of NEC, and the treating physician documents "Stage 1 NEC" or "suspected NEC" based on Bell's Staging Criteria. Documentation should reflect mild systemic and gastrointestinal symptoms without radiographic evidence of bowel necrosis.

• Ensure physician documentation explicitly states "Stage 1 NEC" or provides clinical details consistent with Bell's Stage I criteria.
• Do not use this code if radiographic evidence of pneumatosis intestinalis or portal venous gas is present; instead, consider codes for more advanced stages of NEC.
• Always sequence this code after the primary reason for admission or encounter, if applicable, unless NEC is the primary diagnosis.