What could cause my iguana not to eat?

Two days before he started his shed he refused to eat, a day after we had him stay at a different house for a day, and he was placed in a different cage for a permanent stay when he arrived back home(had him in the bathtub for a few weeks till I could get a bigger cage), and I ume that put him under a lot of stress. I've been feeding him foods such as; bok choy, acorn squash, radish, green beens, ect. His setup is as it should be besides the towel which is being used for substrate. He is only about nine months old, is very active even with the lack of food ate, and amount of defecation varies; sometimes he poops twice other days just once at night and when he only defecates once it's usually a small amount of poo.