Budgie expert adivce needed?

before anyone says, my budgie is at the vet this morning.

last night, as i went to cover my budgie up before bed, i noticed blood on my budgies cage, a bit splattered on the wall and blood on his feathers around his bum, he was quite quiet last night, but he was still squeaking, had a bit of water and had some seed, i did see him poo and it was blood, i called vet and she said bring him down in the morning (nice) i stayed up all night with him and before we nodded off he was still active, this morning he has eaten and has made his usual noises, he has poo'd during the night on his food bowl and its back to normal poo.

any ideas would be greatly appreciated, im just worried i might not come back home with him, he is just over 1 years old and he must have lost roughly a small teaspoon of blood.

thanks