Stacy asks Chase why he was too distracted to give Kayla an appropriately thorough exam. If he was rushed and overworked, it's the hospital's fault. But if it was a personal issue, like, oh, say, an emotional problem, then Chase is liable. Chase doesn't think it's anyone's fault: any doctor would have assumed the stomach pain was related to Behçet's, as he did. Unless, of course, that doctor watched House and knew that vasculitis is never the real reason someone is sick. Stacy isn't buying it, since Chase called Kayla an hour after she left the Clinic. Chase admits that it occurred to him later that Kayla might have had an embarrassing question that his brusque manner discouraged her from asking. He didn't realize this when she was there because he "wasn't thinking clearly." Stacy tells him that's a bad answer, but doesn't ask any follow-up questions about why, say, Chase wasn't "thinking clearly." Instead, she asks Chase what he thinks Kayla might have been trying to tell him. Chase figures she found blood in her feces, which indicates a bleeding ulcer. I'm sorry, but I really don't see how any of this Chase's fault. How stupid are you to not realize that BLOODY POOP is a serious problem that requires immediate medical attention?! Or to know that, but be too embarrassed about it to mention it to a guy who just spent fifteen minutes the day before inspecting every millimeter of your privates? How are you that puritanical and yet still manage to have had sex at least twice? Not to mention that Kayla didn't even have an appointment at the Clinic; she just showed up and ambushed Chase when he was obviously busy with something else. If Chase ends up getting in trouble for that, I'm going to walk up to various doctors on the street and tell them I have a headache and then sue them when they inevitably tell me to get lost instead of asking me follow-up questions.
Kayla never got a chance to return Chase's call, because she was too busy vomiting massive amounts of blood and being transported back to PPTH via ambulance. Chase follows the stretcher into an exam room, and Foreman wanders in and asks why their Behçet's case is back with some decidely un-Behçet's-like symptoms. Chase sticks a camera into Kayla's stomach and finds a bleeding ulcer. He cauterizes it as House walks in, also curious as to why the patient Chase told him was cured is now dying in the ER. "She was fine two hours ago!" Chase says. And just in case you thought Kayla only had the vaculitis and a bleeding ulcer to deal with, her monitors start beeping wildly. She's still bleeding, even with the ulcer closed. House directs Chase to keep looking around Kayla's stomach, and they find a second ulcer. But this one is perforated. Uh oh. "Get her to an OR!" Chase screams. Back in the present, Chase tells Stacy that the surgeons sewed poor Kayla's stomach back up, but her stomach contents had already spilled out all over her body, making her septic and causing liver and kidney damage. Hey, Kayla, you know what's even more embarrassing than telling a doctor you poop blood? When your liver stops working and you turn all yellow with jaundice and then you die. Sort of like how you might feel like a bad mother leaving your kids alone to go to the ER for your severe stomach pains, but it's still better leaving your kids FOREVER because you put a necessary ER visit off a day. Chase says he knows how bad this looks, but that he did do everything "by the book." Stacy leaves to get some coffee.