It sounds like it's time to see a vet about these issues, and soon! There's so many possibilities that we can't possibly guess at the answer in this forum. He could be constipated, or he could have a much more serious problem like organ system disease that's caused him to be painful in his abdomen and to stop eating, which would explain the lack of stool.
Your vet will probably want to run some bloodwork to check out his organs and general health, and likely will want to take some xrays to evaluate his stomach and intestines as well as internal organs. Once you have some more specific information from these tests, you should have a much better idea of what might be going on with your dog, although sometimes more follow up tests may be required. Then you can get him on an appropriate treatment and, hopefully, feeling better soon!
Best of luck!
thanks alot....and we will be getting him to a vet A.S.A.P.
I agree with Dr. Gibson. These symptoms sound serious and you need to see a Veterinarian. In this forum we could only guess as to what is going on. But not eating or drinking, pain in abdomen, reluctance to sit, not having regular or normal elimination habits, knot on his side, all that could add up to something serious.
Please check back in here and let us know what your veterinarian finds.