Obstructed defecation syndrome (ODS) is a clinical syndrome manifest as difficulty in faecal evacuation despite no mechanical obstruction. It is the final clinical pathway of a number of anatomical and physiological pathologies they can result in considerable misery to the lives of the patients it afflicts. Herein, the authors seek to breakdown the syndrome into its component parts, looking first at normal pelvic floor anatomy and physiology; followed by each pathological element; clinical features and investigation; individual management and management of the patient as a whole. It must be stated that correction of anatomy is not the sine qua non, as this does not always correlate to improvement of symptoms. There is a complex interplay of all elements, and a holistic approach appreciating the gestalt principle of "the whole is greater than the sum of its parts" is paramount. Causes of pelvic pain (levator ani syndrome, coccygodynia, proctalgia fugax and pudendal neuralgia) do not fall into ODS and are beyond the scope of this paper.