The anus and surrounding regions. Encompasses both internal and external regions, where present.

http://upload.wikimedia.org/wikipedia/commons/f/fb/Gray408.png

uberon

posterior, posterior end of organism

Although all vertebrates have a digestive tract and accessory glands, various parts of this system are not necessarily homologous, analogous, or even present in all species. Therefore, broad comparisons can be best made under the listings of headgut, foregut, midgut, pancreas and biliary system, hindgut.[uncertain][VHOG]

UBERON:0001353

http://purl.obolibrary.org/obo/uberon.owl, http://purl.obolibrary.org/obo/cl.owl

https://github.com/obophenotype/uberon/issues/507

• proctodeum

• internal anal region
• external anal region