House barges into the OR, immediately pissing off everyone else there. A nurse tries to put a mask over House's face, but he waves her off with a "Stop that!" House gets under the covers and starts looking at Megan's womanly bits, much to the disgust of the surgeon who thinks House is trying to get cheap thrills. "Can you get him outta here?" the surgeon asks Cuddy, who just stands there looking helpless. I'm guessing the answer is no. House shoves a camera up Megan's deal to check out her enlarged uterus, which indicates she was recently pregnant. Sure enough, the camera shows evidence of a secret abortion. The surgeon doesn't see how that has anything to do with the internal bleeding unless the abortionist used a shotgun. "Stop enabling him!" Cuddy orders, and no one in the OR knows what she's talking about, and they probably lost all respect for her a long time ago anyway. House says the abortion is proof that Megan didn't want kids. The secretiveness of it indicates that her boyfriend did. To prevent another accidental pregnancy, House decides that Megan was on the pill.
He explains this to Ben, who's hanging out in a hallway with a totally obvious PERSON WHO WILL BE IMPORTANT LATER in the form of a grieving boyfriend of one of Megan's co-workers, recently deceased. The combination of blood thinners they gave Megan after her hip surgery and the birth control pill no one knew she was taking have led to the internal bleeding, says House. The good news is that Tamoxifen will heal her right up. The bad news is Ben's life. All of it, at this point. Ben refuses to believe this is true, but House says that, in a rare attempt to verify his diagnosis, they tested her blood, and either Megan lied to Ben about wanting kids or Megan's blood lied to House. Every blood cell lies! Ben decides he's done caring about his girlfriend and leaves the hospital.
House barges into some old guy's hospital room and asks how he's doing. "I've got cancer!" the old man replies. House turns the "duh" moment back on the patient, though, by pointing out that he is on an oncology floor. Everybody here has cancer. House just wants to know how much cancer the old guy has, because if he's doing okay, he's about to get patient-napped. What a clever way to get your guitar back, House! As well as a conviction for involuntary manslaughter if anything happens to that old guy. House does take precautions against this, telling the old guy to give him a call directly if he starts feeling sick and not Dr. Wilson, but if the old guy has a heart attack or something, that won't necessarily be an option.