ICD-10-CM Codes 2026 (USA)

• K59.1	Functional diarrhea

• K59.00	Constipation, unspecified
  K59.01	Slow transit constipation
  K59.02	Outlet dysfunction constipation
  K59.03	Drug induced constipation
  K59.04	Chronic idiopathic constipation
  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
  K59.39	Other megacolon
  K59.4	Anal spasm
  K59.8	Other specified functional intestinal disorders
  K59.81	Ogilvie syndrome
  K59.89	Other specified functional intestinal disorders
  K59.9	Functional intestinal disorder, unspecified

Created by Peter Blahut, MD