Toxic megacolon

This code represents an acute, life-threatening complication characterized by rapid, non-obstructive dilation of the colon, often accompanied by systemic toxicity. It typically arises in the context of severe inflammatory bowel disease (IBD) or infectious colitis. The condition signifies a critical medical emergency requiring immediate intervention.

Assign this code when documentation explicitly states "toxic megacolon" or describes the clinical presentation of acute colonic dilation with signs of systemic toxicity (e.g., fever, tachycardia, altered mental status) in a patient with underlying colitis. This diagnosis is often confirmed radiographically.

• Always sequence this code as a principal diagnosis when it is the primary reason for admission.
• Ensure documentation clearly distinguishes toxic megacolon from simple colonic dilation or megacolon not associated with systemic toxicity.
• Code any underlying inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis) or infectious etiology as an additional diagnosis.