my baby corn snake just died, why?

Question
I just purchased an albino corn snake last Thursday, he was a few months old.  
I tried to feed him a small pinkie on Tuesday, (the pet store said they fed him
the night before I purchased him)  and he would not eat.  The pet store
advised me to try again on Friday.  Yesterday he was moving perfectly, and
tonight I went to his cage and he was dead.  I have fresh water in his bowl, a
heat lamp with the temp. registering around 80, using care fresh bedding, and
a cork log to hide under.  I took him out every day to exercise him, and he
moved fine.  He had multiple black areas on his underbelly that I reported to
the pet store, but they said this is normal.  I thought it was waste material
because he hasn't had a bowel movement since I've  had him.  He has however
urinated, I saw it on my shirt, which to me indicated he was drinking.  ( I never
saw him drink) I feel terrible for the little guy and would love your opinion.  
Thank you

Answer
Baby cornsnakes never seem to be consistent on their feeding schedules, and with the stress of moving to a new home would have thrown that one off even more.

They are correct that the black areas are just waste. Yes it would seem that your snake would go #2 more often, but they will wait usually a few weeks before doing so.

Babies do die sometimes with no obvious cause. There have been times I have been at a loss on what happened, especially when I KNOW that everything was good. Sometimes it can be a birth defect, others an internal problem that you or the pet store would not have known about until the snake died. I have lost snakes before and even when I did have an autopsy done, 99% of the time there was nothing I could have known or done to have saved them. I'm sorry you had to have this happen, but don't let it discourage you.