In mainstream movies and TV Shows, actually it's the men who usually get enemas, and mostly it's done to them by females. Take the following shows and movies for instance:
"Gunshy" : Sandra Bullock gives Liam Neeson a barium enema.
"The Road to Wellville" : Nurse Graves(Traci Lind) gives Mr Lightbody(Matthew Broderick) a "colonic wash".
"Little Fockers" : Jessica Alba gives an older black guy an enema at the beginning of the movie.
"Nobody's Perfect"(1968) : A scene where a nurse(Nancy Kwan) is about to give a sailor an enema with a squeeze bulb at the Navy hospital.
"Starved"(ill fated TV show in 2005 on FX): Eric Schaeffer is given several colonics by the beautiful therapist Stella (played by Leia Thompson) * This is the best colonic scene ever on TV IMHO*
"The Simple Life: Season 5" : An episode where Paris and Nicole give enemas to all of the campers trying to lose weight....an episode where I wouldn't have minded being one of the campers, as Nicole was the one sticking the tubes up the campers' butts.
The list could probably go on even further with movies and shows I've probably never seen. But it's women who administer the most enemas to both sexes and this is reflected in mass media. Women are much more likely to give enemas to men because most nurses are females, and females are gentler and more understanding to these types of procedures.