Constipation is an unsatisfactory defecation distinguished by difficult stool passage, infrequent stools or both.
Difficult stool passage may include straining, feeling of difficulty in passing stool, incomplete evacuation, lumpy/hard stools, prolonged time to defecate, need for manual maneuver to pass stool, abdominal discomfort and feeling of anorectal blockade.
Chronic constipation is considered when symptoms of constipation have existed ≥3 months.
Functional constipation has no evidence of structural or metabolic disease to account for the symptoms.