K59.04 Chronic idiopathic constipation

Billable ICD-10-CM code, FY2026.

Applicable to

• Functional constipation

Applies from K59 Other functional intestinal disorders

Excludes1 (never code together)

• change in bowel habit NOS (R19.4)
• intestinal malabsorption (K90.-)
• psychogenic intestinal disorders (F45.8)

Excludes2 (not included here)

• functional disorders of stomach (K31.-)

Applies from K59.0 Constipation

Excludes1 (never code together)

• fecal impaction (K56.41)

Excludes2 (not included here)

• incomplete defecation (R15.0)

MS-DRG index

Defines the logic of DRG(s) 391-392 in MDC 06.

Approximate ICD-9-CM (GEMs)

• 564.09 Other constipation (approximate)

Code annotations containing back-references to K59.04

Back-references to K59.0

• Type 2 Excludes: R15.0 Incomplete defecation ("constipation (K59.0-)")
• Type 1 Excludes: R19.4 Change in bowel habit ("constipation (K59.0-)")

Diagnosis Index entries for K59.04

• Constipation (atonic) (neurogenic) (simple) (spastic) › chronic › idiopathic
• Constipation (atonic) (neurogenic) (simple) (spastic) › functional

Nearby codes

• K59.0 Constipation
• K59.00 Constipation, unspecified
• K59.01 Slow transit constipation
• K59.02 Outlet dysfunction constipation
• K59.03 Drug induced constipation
• K59.04 Chronic idiopathic constipation (this code)
• K59.09 Other constipation
• K59.1 Functional diarrhea
• K59.2 Neurogenic bowel, not elsewhere classified
• K59.3 Megacolon, not elsewhere classified
• K59.31 Toxic megacolon