Defecation is a deathgrind side project formed by Righteous Pigs guitarist Mitch Harris and ex-Napalm Death drummer Mick Harris in 1987. Mitch Harris was the guitarist, bassist and vocalist, and Mick Harris was the drummer and vocalist as well, until Mick left the group shortly after their first album Purity Dilution was released.
Before Defecation started, Mick was the drummer for Napalm Death, and Mitch was the guitarist for Righteous Pigs. The two were pen pals and decided to start the project. They formed Defecation in 1987 and released Purity Dilution on Nuclear Blast Records in 1989.