Something is definitely wrong. Mine hasn't pooped (except for a vet's enima, and a second vet's 'stimulation') in one and half months. He has been to two vets. The last vet did a poop test and found very elevated parasites - protozoa, pinworms and roundworms. I don't know where these came from since he has been very very healthy for his first year without any major change of lifestyle.
Get his poop tested asap - and get him to a vet to 'stimulate' a poop. Our vet used a long Q-tip with maybe some vaseline that was stuck in a little ways and while it was in, it made Beardo push out a little puddle, then when the long Q-tip was removed, he pushed out a humungous poop. However, my Beardo is still unwell. Just got some very expensive medicine today. He still doesn't poo - but then again he is only eating 5% of normal volume - again all other environmental factors are fine (i.e. the right type of light, right type of substrate, right type of heat, right type of food).
Get him to a vet. My search tonight is advice re opening his mouth and feeding him liquid medicine.