**K59.0 — Constipation** is defined as infrequent, hard, or difficult-to-pass stools. K59.00 covers unspecified constipation; sub-codes K59.01-K59.09 specify slow-transit, outlet dysfunction, drug-induced, chronic idiopathic, and other forms.
A common chronic complaint, particularly in elderly populations, pregnancy, and patients on opioid therapy.
Belongs to **Chapter K** — Diseases of the digestive system (K00-K93).
