That absurdist nonsense is medical slang. "Chasing zebras" refers to medical cases where symptoms of a rare illness present themselves as a more common illness. Like Foreman says in the pilot episode: "If you hear hoof beats, you think horses, not zebras." "Circling the drain" is exactly as it sounds: patients on the verge of death.
That title perfectly described House: doctors who are attempting to diagnose the undiagnosable. It also sounds like the title of a Salvador Dali painting, or a doctor show starring Dali himself, where all his cures involve rearranging people's guts into surrealist shapes that his underlings don't understand, but they don't want to look stupid, so they just nod in agreement.
"The mangled gallbladder with a lady's face represents ... his lymphoma? No! His disconnect from a post-industrial society!"
House may ultimately have been the boring choice, but at least it wouldn't mislead people into thinking they were going to watch an Oscar-baity documentary about a man who has lost control of his life but rediscovers himself as he hunts pinstripe ponies.