Is my Teddy Bear hamster dying of old age?

I know EXACTLY what you mean. 2 of my favorite hamsters (both teddy bears) died from that :'( it is a disease called wet tail and sneaks up on you. We were told to treat him by giving him vitamin C drops but he passed away anyways. But he was a VERY old hamster- 4 years! So i would suggest doing some research on that disease. I hope your little guy makes it <3 Teddy bear hamsters are the best!