Bill Lawrence and a few of the writers jokingly claim that Neil Flynn (The Janitor) has never actually spoken a line from any script. A fourth season script reportedly even contained "(Whatever Neil says)". While Lawrence's comment is certainly an exaggeration, it illustrates how much of his performance is spontaneous.
Through the first season, the cast and crew, especially writer/creator Bill Lawrence, were so sure that the series would be canceled by the end of the season, that a plot twist was created for use when they'd have a forced series finale. This plot twist noted the fact that the Janitor, Neil Flynn's character, never directly spoke nor was spoken to by any other character than JD, Zach Braff's character. Therefore, the Janitor would be a complete figment of JD's imagination. This idea was kept up into the second season, still in fear of cancellation, until Flynn asked Lawrence to be able to finally interact with another actor on the series. (Although Elliot actually throws a cup at him in the 6th episode and sarcastically says "SORRY!", in episode 11 he gets punched on the balls by a little girl and in episode 15 the janitor teases the nurse with the vacuum cleaner)
During any episode where J.D. is not the narrator, he must usually make physical contact with the person who will be the narrator to pass off the responsibility. When narration is passed back to J.D. at the end of the episode, the former narrator must contact J.D. to give it back to him.
The show has some connections to the abbreviation TCW. Donald Faison starred in Remember the Titans (2000), whose high school was TCW. JD later dates a girl whose is called TCW (Tasty Coma Wife) and then it is shown in the episode "My No Good Reason" as being from a school with the initials TCW.
Creator Bill Lawrence has said in interviews that he wanted "Scrubs" to be almost like a live-action The Simpsons (1989), not only in the style of humor but also with the numerous high-profile guests and a fairly large cast of recurring characters. In a 2006 episode, J.D. commented that Grey's Anatomy (2005) was so realistic that "it's almost like someone was watching our lives and put it on television," a joke borrowed from an early '90s "The Simpsons" episode saying the same of Dinosaurs (1991).
The third floor of the hospital where scrubs is shot has been renovated to be offices for the crew and producers, and dressing rooms for the cast. The show's staff and cast are allowed to bring their dogs to work, and they all stay on the third floor. Donald Faison who plays Turk on the show was not a fan of the dogs, and was seemingly left quite a few presents by the dogs right in front of his door. But the truth that he still may not know is it is really fellow cast member, Robert Maschio ("The Todd"), who collects the dog "two-sies" he runs into through out the day and places them in front of Donald Faison's dressing room door. Maschio revealed this for the first time while doing video for the DVD release of the show; it was put on the third season DVD special features. During Fasion's interview he was still unaware it was Maschio and not the dogs leaving him the presents.
Many episodes contain some form of the phrase "And there it is" in its dialogue, usually when the moral or theme of that episode is revealed. Usually J.D. delivers this line, but sometimes other characters are given this responsibility.
Several characters, including Colonel Doctor, Snoop Dogg Intern, and Dr. Beardface started as extras and were referred to by these names by the cast and crew who did not know their real names, but were later written into episodes with speaking roles.
Dr. Cox's trademark nose rub before crossing his arms is a reference to Robert Redford in The Sting (1973). Redford used it as a sign for "It's OK" or "Go Ahead." John C. McGinley added it himself as a tribute to the film.
A list of the languages the characters know as revealed throughout the episodes. Elliot speaks German and French, Turk knows very little French and he learns Spanish for Carla. Both Dr. Cox and Carla speak Spanish, and the Janitor knows sign language and also speaks Spanish and Korean.
As an experiment, the Season 5 finale "My Transition" (#5.24) was finished and aired in High Definition. Scrubs (2001) is the first network show to complete an on-line edit in Final Cut Pro SD, and with this episode becomes the first network show to on-line in HD in Final Cut Pro. However the show continues to be produced in Standard Definition. According to the producer, Randall Winston: "After a lot of teasing, yes, the HD was an experiment, for everyone really. We will not be doing any more HD - there is a cost that no one is interested in covering and there is debate, not among us here at the show, about how the quality stands up. I don't think that we can get the look that the show is designed around [by using] tape."
The network leased and refurbished a closed hospital (North Hollywood Medical Center in the San Fernando Valley in California) for the program. The lower and upper floors of the hospital are used as other sets and production offices.
At the beginning of the second season, a longer intro was introduced that included all of the characters in the show, and not just the doctors. It was quickly scuttled when NBC decided to extend the length of the episodes in an attempt to win more viewers.
For the first eight seasons almost every episode title begins with the word "My". Notable exceptions are the episodes entitled "His Story", "His Story II", "Her Story", "Her Story II", "His Story III" and ''His Story IV'' These episodes each contained internal narration from a character other than JD. (Dr. Cox, Turk, Elliot, Carla, The Janitor and Dr. Kelso respectively). There is also "Their Story" in which we hear the thoughts of Ted, the Todd and Jordan. In "Their Story II" the thoughts of 3 interns are followed. Starting with season nine every episode title starts with "Our".
JD's father's (John Ritter) final line when he asks JD to pull his finger and then says, "I pooed a little," was totally improvised and Zach Braff had to bite the insides of his cheeks to stop himself laughing.
The only girls names Dr. Cox has used more than once are Lily, Ginger, Shirley, Gidget, Marcia, Gloria, Janice, Betsy, Carol, Toto, Nancy and Brittany, which JD points out to Dr. Cox, who responds with "Today I'm going with famous pop-stars."
Season 8 was originally supposed to be the show's finale, but creator Bill Lawrence decided to add a 9th season (and not doing a spin-off). As a result, the show changed significantly. Season 9 became known under the title "Scrubs: Med School", J.D. was no longer the central character, a lot of new actors were cast and the episode titles no longer started with "My...", but with "Our...". The whole show was eventually canceled after season 9.
While Bill Lawrence, the series creator, stated on Facebook that the janitor's real name was Glenn Matthews, his is in conflict with season 3 episode 8 where JD sees the janitor playing the role of the Transit Cop in the movie The Fugitive (1993). At the end of the episode the janitor admits that it was him playing that role. The role of the Transit Cop was played by an actor named Neil Flynn indicating that the janitor's actual name also had to be Neil Flynn. However, it is possible that, like may actors, Glenn Matthews went by a stage name. In this case Neil Flynn may be the stage name of Glenn Matthews.
Unusually for a series, no one character appears in every episode. The closest to hold this achievement are John C. McGinley (Dr. Cox) and 'Donald Faison' (Turk), who are absent from 3 episodes each. Following them are 'Ken Jenkins' (Bob Kelso) and series star Zach Braff (title character, J.D.), who are absent from 7 and 8 episodes respectively.
The trivia item below may give away important plot points.
It was presumed to be revealed in the season 8 finale that the Janitor's real name is Glenn Matthews. However after J.D. walks away, someone walks by the Janitor and calls him "Tommy". In a Facebook post by Bill Lawrence on April 13, 2011, he confirmed that the janitor was telling the truth when he revealed his name as Glenn Matthews.