Chinchilla not pooping

Hello there! I am new to this community but have had my chin babies for about 6-7 years now. I just noticed this morning that my boy chinchilla is not pooping at all. Also, he hasn't eaten anything but drinks his water here and there. He is being much lazier than he normally is as well. Overall, he looks healthy, there is no oozing of anything anywhere, eyes are clear and ears aren't red. Although a few times i noticed that he would make this tight heaving position and look strained with his ears down and make these tiny little noises. There is no way I can get him to the vet, I don't know what is wrong with him, if he is constipated or what. What can i do to help him

Thank you so much in advance to any help or guidance