The second stage of libidinal development which follows on from the Oral stage (q.v.) and characterises the child’s development between 18 and 48 months. It is followed by the phallic or genital stage.
In Three Essays on the Theory of Sexuality (1905), and his paper “Character and Anal Erotism” (1908), Freud observed that as children learn to control excretion so they undergo a primary and fundamental socialisation which is allied to their learning to obey and to please their parents. The production of faeces when required can be seen as a gift to the parents, just as their withholding can be seen as a rebellion. Children must also learn not to play with faeces, so to master the concepts of ‘dirty’ and ‘clean�…
Clark, Robert. "Anal Phase". The Literary Encyclopedia. First published 22 October 2005
[http://www.litencyc.com/php/stopics.php?rec=true&UID=42, accessed 23 March 2017.]