Stage 1 necrotizing enterocolitis

This code represents the initial stage of necrotizing enterocolitis (NEC), a severe gastrointestinal disease primarily affecting premature infants. Stage 1 NEC is characterized by mild, non-specific symptoms such as abdominal distension, feeding intolerance, and occult blood in stools, without radiographic evidence of pneumatosis intestinalis or portal venous gas.

Use this code when documentation clearly indicates a diagnosis of Stage 1 NEC, often based on Bell's Staging Criteria. This applies to neonates presenting with early signs of NEC where imaging studies do not yet show advanced disease. Supporting documentation includes physician notes detailing clinical presentation, physical exam findings, and initial laboratory results.

• Ensure the physician explicitly documents "Stage 1" or "Bell's Stage I" NEC.
• Do not use this code if radiographic evidence of pneumatosis intestinalis or portal venous gas is present; those indicate higher stages.
• Always sequence this code as the principal diagnosis if it is the primary reason for admission or encounter.