The anus is the opening at the end of the bowel. It is made up of the last few centimetres of the bowel (anal canal) and the skin around the opening (anal margin). During a bowel movement, the muscles of the anus (sphincters) relax to release the solid waste matter known as faeces, stools or poo.
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This information is reviewed by
This information was last reviewed July 2020 by the following expert content reviewers: Dr Chip Farmer, Colorectal Surgeon, The Alfred, The Avenue and Cabrini Hospitals, VIC; Tara Faure, Lower GI Nurse Consultant, Peter MacCallum Cancer Centre, VIC; Dr Debra Furniss, Radiation Oncologist, GenesisCare, QLD; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; Max Niggl, Consumer; Julie O’Rourke, CNC Radiation Oncology, Cancer Rapid Assessment Unit, Cancer and Ambulatory Support, Canberra Health Services, ACT; Dr Satish Warrier, Colorectal Surgeon, Peter MacCallum Cancer Centre, VIC.