Thanks for your question.
In Canada, the law states that the age of consent for anal sex is: 18 years old. The law states that all people participating in anal sex must be age 18 or over.
This law has been protested by many LGBTQ activist groups as unfairly criminalizing sexual activities between same sex partners. The law is being reviewed by federal government for being unjust, and in June 2017 Prime Minister Justin Trudeau stated that wants to repeal the law. However, the law is still currently in effect.
The age for other kinds of sexual activities is age 16. More info on that here.
If are under age 18, and interested in anal sex, then check out our page on anal play.
Hope this helps. Please feel free to comment below or submit another question.