Female hamster has a swelling(with picture)

[Ceku]

My female hamster has a swelling next to her anus.She is 1 year 7 month.Species is dwarf roborovski hamster. Five days ago, I saw blood in her butt and took her to the vet. Vet said the blood was fresh and it could be caused by constipation and she look like healty. After 4 days, this swelling suddenly appeared. By the way, she's moving and acting normal. She's also not pregnant. Please help me. I photographed the swelling. The swelling is neither hard nor soft.
Every poop and pee are normal. She runs a little bit in the evening. It's good that she eats. I'm not sure about the water.I also wiped the swelling with thyme tea, but she didn't like it at all and immediately she dried the soaked places.
Please help me i love her so much.

https://ibb.co/5Gr1LkK

[Tubbytiger]

If you are concerned for her take your hamster back to the vet immediately. If the vet does not treat her, go somewhere else, she deserves proper veterinarian care. Do not give up on this little one!