Online symptom checkers

I've been fighting a nagging cold (or maybe something worse) for over a week. Today I did something morbidly fascinating: I looked at an online medical symptom checker. At first I was interested to see if I might have something worse than your average cold or gastro. Then I started adding extra symptoms to see if I could get it to diagnose any extreme diseases. Unfortunately it kept the boring, common ones at the top of the list and the more interesting, exotic options stayed further down. I think there must be some statistical determinate programmed to balance out the symptoms I was inputting. However, I  caught myself thinking at one point that the computer was telling my I had a 94% chance of having appendicitis. Luckily I heard my own absurdity before I rushed off to the emergency ward. But it did make me think about how we have to be careful not to believe what we are told just because we see it in print. So, it seems to turn out that I am not dying of anything very exciting, and am just fighting a common winter cold.