swellings on hamster

Question
I have  recently bought a  youg female hamster and have notices that its backside recently seems rather large. the hamster is ok and is eating normally and plays in it wheel as normal.its seems in good health but for this. is this normal  

Answer
If you mean that the buttox looks rather large, there's a chance your female could be a male.

http://www.petwebsite.com/hamsters/sexing_hamsters.htm

The picture of the syrian female didn't come up for me, but she would have nipples on her tummy and no protruding buttox.