whats wrong with my ferret

my ferret punkie is almost 3 years old a few days ago her cage mate passed away from old age. today i noticed her anus is swolen and red,could this be from stress or a more serious problem?

Your ferret's swollen butthole is unlikely to be stress related.
   
Can she take a crap?
   
If not, see the vet ASAP.
   
She may have a prolapsed rectum. Try feeding her nothing but wet food and start cleaning her butthole for her.
   
You may also want to try putting some Preparation H on a Q-tip and wiping it on her anus once or twice a day.
   
I have not tried that myself but have heard others have had success with it. It's an anti-swelling med so it's worth a try.