House Season 1 Episode 3 : Occam’s Razor

A college student named Brandon (Kevin Zegers) collapses after having sex with his fiancée. His symptoms seem too numerous to be explained by just one disease. Foreman and House each suggest different diagnoses and argue that his own respective theory better conforms to Occam's Razor. But then Brandon's white blood cell count drops, proving both doctors wrong. At the clinic pharmacy, House theorizes that Brandon was accidentally given colchicine instead of cough medicine, which explains all of his symptoms aside from his cough. House gives Brandon the cure, and he immediately begins to recover, yet the doctors are unable to find the source of the colchicine. However, when Brandon comments that his old cough medicine did not have letters on it like his current pills, House discovers colchicine pills that look similar to cough medicine, revealing the source and confirming House's diagnosis.