Editing Excretory system (section)

===Gastrointestinal tract===
{{Main|Gastrointestinal tract}}
The large intestine's main function is to transport food particles through the body and expel the indigestible parts at the other end, but it also collects waste from throughout the body. The typical brown colour of mammal waste is due to [[bilirubin]], a breakdown product of normal [[heme]] [[catabolism]].<ref>{{cite web|last1=Dr. Tim Kenny|title=Jaundice|url=http://www.patient.co.uk/health/jaundice-leaflet|publisher=Patient.co.uk|access-date=25 December 2014|archive-date=18 December 2014|archive-url=https://web.archive.org/web/20141218183344/http://www.patient.co.uk/health/jaundice-leaflet|url-status=dead}}</ref> The lower part of the large intestine also extracts any remaining usable water and then removes solid waste. At about 10 feet long in humans, it transports the wastes through the tubes to be excreted.