In all possibility, it could be a number of problems. I would definately think about parasites. If you decide on getting another one, take it to a vet and get a fecal test done. It isn't very expensive and is done in about 15 minutes. I do them ALL the time. I would get a test done on all of your guys/ girls to make sure everyone is ok. The poo should be fresh, no more than 24 hours old (they might want an extra fresh sample so they can test for Giardia, a protozoa found in dirty conditions, not necessarily yours, but previous owners. They need a fresh sample so they can do a direct smear and see the little protozoa moving around.) Take individual baggies labeled with date, name of animal and your name, and put a sample from each animal in each baggy. If you can't get it to the vet in a few hours, stick it in the fridge until you can take it. Another protozoa is Cryptosporidium, which can spread through your ENTIRE collection like wild-fire. Even people can get it. Not fun. If they end up having that, there isn't much of a cure except supportive care, and 95% of the time they DO NOT make it. I did a fecal on my rat when I bought her (she's a pet, not food) and I thought she had Crypto, but it ended up being Coccidia. That stuff takes 4+ weeks to get rid of. Well, hope this helps, and get all of them to a vet ASAP so nobody else succumbs to what the Iguanas had. Good luck. If you have any other questions regarding the medical aspect of this stuff, just ask.