Iguana constipated?

Check the temperature of it's enclosure. It's probably to cool. Raise the temperature. Try to give it another bath in warm water but this time rub it's belly for about 5 minutes in smooth, slow, gently strokes. If it doesn't deficate in 24 hours it isn't because it's cold. It probably eat a piece of it's bedding, or it can be a parasite. It can also be caused by MBD (metabolic bone disease). If it doesn't deficate in 24 hours then take it to the vet. The longer it's constipated the most serious it will get. I hope it's just the temperature and you find out the problem.