Are you talking about the dark markings on the belly?
If you are, that's pretty standard for a normal. Some normals will have very clean white bellies, others will have very busy checkered ones.
I don't see anything particularly wrong in the picture. But its still kind of a poor picture. I can't see the belly in the shadows very well. Scale rot looks like something is eating away at your snake's scales bit by bit.
If it is scale rot, you can put some diluted betadine on it. If its really minor, it will go away with the next shed.
Sent from my DROID RAZR using Tapatalk 2