I don't know what is going on between two of the people responding here but I have had and bred dragons as a hobby for several years. I listed my web site at the bottom of this reply. I think you may be having some problems with minor impactions and cage temps. Here is some quick background info and some sugggestions that might work for you.
What are you using to measure the temps in the cage and what size cage. A 10 inch dragon needs a least a 30 gallon or larger cage. An adult dragon will need at bare minimum a four foot long cage. Use a digital thermometer and measure the closest heat source (basking spot)and the spot farthest away. The hot spot should be around 110 and the cool spot should be 75 to 80 degrees. If the overall cage temp is too hot and too small your dragon might be digging to try and find a cooler spot to get out of the heat to cool down.
Substrate for a 10 inch dragon can be any non loose material that can be removed, cleaned, and sterilized or just thrown out and replaced when soiled. Things like tile, news paper, retile carpet etc. At 10 inches the only loose substrate that can be used is clean, dust free, play sand that has been run through a fine screen to remove any larger pebbles. I personally only use this when my dragons reach 15 inches long. Very porous materials like plaster are very hard if not impossible to steralize and othe loose substrates like clci sand, walnut shell, birdseed can cause impactions.
Dragons grow though out their life but most of the growing is done by 18 months of age. The proper food ratio is 80% protien and 20% veggies...all they can eat. As they get closer to 18 months you can begin to adjust thier diet to 20% protien and 80% veggies. At 6 months and 10 inches the 80% protien and 20% percent veggies are what you should be following.
Good protien sources are crickets BUT they can not be any longer then the space between your beardies eyes. My guess at this size dragon would be 1/2 inch crickets. Anything larger can cause impaction which is not just uncomfortable for your dragon but can cause permanent paralysis or even death. You mentioned that he is getting LARGE crickets. I think that is the problem. They are getting stuck in his digestive track and working thier way out slowly. This accounts for lack of appetite and pooping only every three days. Getting spoiled on wax worms (they are like feeding your dragon candy bars every day..not good) could also be causing the problem.
If you are getting your crickets from a store try looking for a vender that can ship the correct size crickets directly to your door. You should be able to get 500 or more for a bout $15 or less delivered.
You can also consider silkworms as a protien source. They are high in protien and low in fat. The only problem is they can get expensive and are not always available.
For veggies collard greens are the best followed by dandilion turnip and mustard.
If you have any other questions feel free to contact me through my web site.
http://www.jewelsdragons.com/
I hope this helps!