A lot of people think that doctors have a nice clean job...those white coats and all. Well I can't think of a specialty that won't at the least be exposed to poop, vomit or bodily excretions at some point. As an intern, I was cleaning a patient's foot ulcer, pried apart a couple of toes and found some maggots there. The patient told me that they helped keep the wound clean last time. While that was probably true, I opted for a more conventional wound care plan.
As for ideas for the show:
1) Gastroenterologists- especially when working in the endoscopy suite. Colonoscopy is reasonably dirty as few patients have prepped their colon totally free of poop. A patient's identity would not need be disclosed as all the camera work could be focused on the host, doctors and the video camera of the colon. Air is pumped inside the colon to get a good look. What air goes in must come out, usually loudly. One gastroenterologist would tell the patient, "Let 'er rip." Heck, Mike seems to be close to the proper age for having a colonoscopy screening... perhaps he could be patient. Maybe the producer can hold this fate over his head if he doesn't keep the show's ratings up! The patient, who receives pain medication and a mild sedative, is awake, fairly lucid and able to comment.
2) Pathologists and their technicians - a pretty dirty job when dealing with surgical specimens and autopsies. Surgery is dirty and bloody, but that sort of thing is pretty well covered on TV already.