15 grams is NOTHING, I have 200 grams snakes that loose that much in one bowel movement.

Minimize stress, make sure all hides are tight and downsize the enclosure if necessary, (works well with males to keep them eating during that time of the year), and most importantly be patient, at this size he could go a year without food.

If the animal is very active somethin tells me he is not feeling secure (whether it's over handling or your husbandry) there is something that needs to be looked at.

Sent from my SM-G900V using Tapatalk