Obstructive defecation is observed in approximately half of all patients with functional constipation. Functional constipation has been related to alterations in intestinal motility (slow transit constipation) and to pelvic floor disorders leading to obstructive defecation associated with anatomical alterations of the pelvic floor (rectocele, posterior perineal hernia, enterocele and sigmoidocele, internal rectal intussusception, occult mucosal prolapse, solitary rectal ulcer and descending perineum syndrome), or obstructive defecation without anatomical alterations (pelvic floor dyssynergy or anismus). The diagnostic methods used (history and physical examination, colonic transit time, balloon expulsion test, proctography, anorectal manometry and electromyography) are reviewed. Conservative medical treatment and the indications for surgical treatment and its results are also discussed.