passed corn snake

Question
I just had one of my snakes die. I am very sad that he passed and feel really guilty as I noticed him acting weird about a week ago. He/she was a young corn snake, about 1.5 feet in length. Just about a week ago I noticed he was not as active as he usually is and he just wasn't himself. His body seemed "mushy" and then 2 days ago I noticed a bulge (dark in color, as he was light colored)towards his vent. Unfortunately this was on Friday night and no reptile vet was available. Well, today (monday) he is dead. What could have been the cause? What could I have done? Could it have been the substrate? Aspen chips. Someone told me it was because he didn't have a light. But he did have a heating pad, and would get sunlight through the window for a portion of the day. I would definatley like to get another one and don't want this to happen again. I also have a king snake and don't want the same thing to happen to him.

Answer
Hi Alex
I am so sorry to hear about your loss. It breaks my heart just as well when something happens to one of my animals.  I will tell you that you did everything right.  Aspen shavings (not chips) are a good choice for substrate.  I use it in all my snakes cages and have for years. A heating pad is just fine. You don't need a light if you have one and the natural sunlight is very good too. He was a very young corn snake and he might have been born with an internal defect. Of course it would have helped if I had seen this "bulge" on him. It sounds very much like an internal infection/impaction.  Be sure you are only using shavings and NOT chips. I am sure your kingsnake will do fine. Take care and cheer up :-)