By way of background, I provide administrative support for my supervisor, who is the "manager" of several departments in our division. As such, when people call boss's phone number, it rings to my desk first and I get her voicemail messages, which I just forward on. This includes normal business calls and calls from co-workers about things like calling sick to work, etc.
Most people leave call-in messages that go something like "I'm not feeling well and will be staying home today" or "I'm staying home with my sick kid." Occasionally they leave a little more detail like "Feels like I'm coming down with the flu" or "The allergies are acting up again" or something similar. All fine. However, there is one co-worker who always gives way, way too much information. Like "I was up until 1:00 vomiting and then I got <unpleasant intestinal symptom> and had to stay in the bathroom all night. I've managed to keep some juice down, but it feels like the vomiting might start up again. I also might have a fever. I've been chilly and sweaty all night and my stomach hurts. I'll stay home so I can be close to the bathroom...." etc, etc, on and on and on. Please note that this was a sanitized version of co-worker's typical message. Some of her messages have been so detailed and so graphic that I feel the need to take a shower and two aspirin after listening.
The thing that's funny (sort of) is that boss doesn't really care why people call in sick. She doesn't get upset about people calling in and would never question someone about whether they needed to stay home. Some people actually say they're "taking a mental health day" or "catching up on sleep" or something, and it's fine.
My question is, how do I politely and professionally communicate to co-worker that I do not need or want this much information in her call-in messages? I'm really at a loss here....