ICD-10-CM > K00-K95 > K55-K64 > K59 > K59.0 K59.0 Constipation Non-Billable/Non-Specific Type 1 Excludes fecal impaction (K56.41) Type 2 Excludes incomplete defecation (R15.0) Codes K59.00Constipation, unspecifiedK59.01Slow transit constipationK59.02Outlet dysfunction constipationK59.03Drug induced constipationK59.04Chronic idiopathic constipationK59.09Other constipation