no doubt in my mind that it is impaction...tomorrow youll notice that his legs are paralised.. but dont worry its reversealbe..
first off get him off of sand ( if hes on it) give him a warm bath AT LEAST daily and feed him alot of greens and wax worms.. wax worms arent the greatest but it will give him the runs.. get him off of worms with an exosceleton ( no meal worms/ king worms) and in about a week you should notice a difference...
( symotons )Straining to defecate, tremors, twitching or paralysis of rear legs.
(result) Slow painful death
(cure) Warm baths and gentle massage. Some vets may do an enema if the animal is large enough, depending on the cause.
Impaction can come from feeding food that is too large to be digested and passed as well as ingesting other items that cannot be digested such as wood, sand and synthetics.
(prevention) Proper sized food. For crickets, make sure that the cricket can fit easily between the Beardies eyes. Other items like worms and roaches should also be small enough to be easily digested. Super worms and meal worms are hard to digest and need to be fed in moderatio
taken off of
http://www.beardiedragon.com/pages/C...alth_Table.htm
under impaction theres a few links you should follow...
just in case im rong ( dont think i am ) id still do what the above ppl said just in case it is MBD also look at the link under MBD and it will give you more tips and links
it really does sound like impaction to me cause you said it was the back legs.. when a beardie gets impaacted my guess is the intestines push on a nerve that paralises the back legs.. it may also cause tremors.. so thats my educated guess.. bascialy hes got to poo it out.. but the baths and massages will help it loosen up and work its way through