K59.1

Functional diarrhea

Billable / specific

K59.1 is a billable, specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes in FY2027.

Excludes1

Not coded here — never report together with this code.

diarrhea NOS (R19.7)
irritable bowel syndrome with diarrhea (K58.0)
change in bowel habit NOS (R19.4) (from K59)
intestinal malabsorption (K90.-) (from K59)
psychogenic intestinal disorders (F45.8) (from K59)

Not included here — may be reported together when both conditions exist.

certain conditions originating in the perinatal period (P04-P96) (from K59)
certain infectious and parasitic diseases (A00-B99) (from K59)
complications of pregnancy, childbirth and the puerperium (O00-O9A) (from K59)
congenital malformations, deformations and chromosomal abnormalities (Q00-Q99) (from K59)
endocrine, nutritional and metabolic diseases (E00-E88) (from K59)
injury, poisoning and certain other consequences of external causes (S00-T88) (from K59)
neoplasms (C00-D49) (from K59)
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) (from K59)
functional disorders of stomach (K31.-) (from K59)