Medical advice over the internet
First things first. For anyone looking to receive a diagnosis over the internet for a medical issue, whether that be for themselves or for an animal, it's imperative that you consult a professional. The majority of people who will answer your question on the internet are not professionals, and many symptoms can cross over between a wide variety of conditions.
The task at hand
Okay, now onto the question at hand. If your hamster has a long red and bleeding thing coming out of her butt, it's a sure sign that something isn't right! It sounds serious, so I'd definitely contact a vet for issues like this. That being said, let's have a look at what it could actually be:
- The most obvious answer to this question is that your hamster has a prolapsed rectum. What that means is that her intestinal tract has turned in on itself, and is now hanging out of the anus.
- Alternatively, she may have eaten something that she shouldn't have that has caused damage internally.
Both of the above conditions are extremely serious and definitely life threatening. There is no home medication available for these types of conditions, and immediate veterinary advice should be sought. I sincerely hope your hamster recovers!