Well my snake always soaks when he sheds, even with humidity at 70%. He sits in his water until he gets cold then goes into his warm hide until he gets too warm. Then back into the bowl. Rinse and repeat.

If you sprayed PAM I doubt it is mites. I sprayed it and the next day all mites were dead. Havn't seen them since.

I am not that experienced, but if the snake is constipated it wouldn't be pooping I wouldn't think. The fact that it is we make me not worry about it.

How are you keeping humidity in your tank? In my tank when I misted I had it set up so it stayed at 70ish% the rest of the day.

Its probably just shedding.