Hmmm...
How long between meals (regurges)?
There are several things that can and do cause regurges, handling too soon after eating and environmental teps that are too high or too low are the top of the list with internal parasites coming to a close third followed by other illness, infections and other things, like psychological issues etc.
What are your temps, both hot side, cool side and the night time drops?
How you heat also plays a role in digestion, as snakes need bottom based heat source for digestion - heat pad,
UTH etc. many times, lights alone won't do the trick.