Monitor seems off help please.

[Tyguy35]

Hello, so my sav has been acting a little strange lately. I find when he eats and swallows makes a noise almost like he choked not very loud. About a week later (now) he doesn't have a huge appetite and sometimes when he breathes out it's like a little tiny sneeze usually happens twice in a row then not for a little bit. His stomach is quite large and stiff and I have not seen him poop in a while. I foud a small poop today and it was green. I tried to get him to go fully but he did not. His temps are 140-45 basking ambient goes from 80-95. His cage is 8ft by4 by4. Been eating mice gizzards chicken hearts and liver. I will be getting baby chicks next weekend which will be a large part of the diet. He also gets superworm. Sometimes shrimp but they dot care for it. Do you think he is constipated?