Wing Bleeding

Question
Hi, today my male budgie hasn't been eating properly and was experiencing some diarrhea. It has been hiding from me under sofas and is really restless. I had two budgies before but i was keeping it for a friend. They had grown quite fond of one another but now i have to separate them to give it back to the friend. Yeah.. and, the budgie lost a feather today and there was blood on it. I haven't had a budgie for long and it kinda freaks me out.

Answer
In regards to the feather, he probably lost a blood feather.  As the name suggests, a blood feather is a feather that has a blood supply running down the shaft.  When these are lost, plucked, or broken, there is often a bit of bleeding.  It's usually not much.  If you're worried that there's a lot of bleeding, try dusting him with some flour.  It sticks to the wet blood and helps it clot and slows the bleeding so that it can start to heal.

If he isn't eating much and is having diarrhea, he is sick.  I would call a vet and get him seen.  Meanwhile, make him comfortable.  Put him in a dark, quiet room and keep the cage covered so that he can rest.  Keep the room warm and humid; this makes the bird more comfortable and makes it easy for him to breathe.  Even if he isn't having trouble breathing, it's good for him and will keep his stress level down.  Make sure that he has clean water and fresh food.  You may also want to get him some vitamins.  You can get drops at most pet stores that you can put in the water.  

Avoid over-the-counter medicines.  These are usually placebos at best, and sometimes do more harm than good.  Especially avoid anti-biotic medicines.  These are usually so weak that all they do is allow the bacteria to develop an immunity so that when he really does need anti-biotics, they won't do any good.  It costs a lot more to get these from a vet, but they're much safer and work better.

Let me know how he's doing in a few days, okay?
Best of luck!