How quickly does endometriosis comes back after having laparoscopy?

Varies. Some women experience recurrent symptoms as soon as a few months after laparoscopic treatment of endometriosis - some women have recurrent symptoms a few years after treatment and a few women never have significant symptoms again.
Depends. 1. How extensive was disease? 2. What technique was used to remove disease -->ablation? -->excision? For either technique, disease is often left behind, particularly microscopic disease and is generally recommended to use post-operative medical therapy (adjuvant) like lupron-danocrine to burn away any residual disease.