Last week's episode was especially hilarious. I even burnt myself a personal copy on a DVD. In order to find the name of the episode, I ran to the official website. This is the show's sixth season and last week was the sixth show of the season. It was entitled My Musical and here's what the site says:
'Sacred Heart is turned into a full scale Broadway stage when Patti (original "Avenue Q" cast member Stephanie D'Abruzzo) checks in complaining of hearing incessant music. While trying to determine the cause of this strange complaint the residents of Sacred Heart star in their own musical. Carla and Turk tango over her decision to be a stay at home mom or to return to work, while Elliot struggles with telling J.D. that she doesn't want to be roommates with him anymore -- both girls hope that the boy's "Guy Love" will help them through the rough patch. All the while the staff wonders if life would be happier if everyone was in constant harmony.'