Constipation and defecation may be considered as the last taboo. The inability to defecate or to achieve this only by digital evacuation has never been a popular topic among patients and doctors. Application of tests from the colorectal laboratory has made it possible to study the function of the different parts of the colon and the mechanism of continence. We consider transit studies, defecography, EMG, and anal manometry, all useful as diagnostic procedures for functional constipation. Several causes of functional constipation can be distinguished in slow transit and difficult evacuation or colonic inertia, spastic pelvic floor syndrome, rectocele and intussusception. This article presents our view of the assessment and management of functional constipation.