That's a relief.I think it was a blockage.
I wiped the area with a warm cloth. I then put him into a small, unfamiliar pen to encourage him to move around and explore. Then I moved him and his sister into their own cage with hay on a solid floor. I took out the nest box and put in easily accessible food and water bowls. He wasn't eating any pellets or drinking any water because it was all outside of the nest box and he never left the box. He was surviving only on his mother's milk. Now that he's out of the nest box and moving around, I think it helped get his system moving again. I checked his bottom just recently and the swelling has seemed to have gone down, also, he has solid, normal colored droppings.
It definitely isn't vents disease, the pus was coming directly from his genital opening. I think maybe it was urine, but because he wasn't eating or drinking, the color and substance was milky. I know that sometimes kits get blockages, I'm hoping that's all it was. I'm still going to be monitoring him closely, he isn't as active as his sister yet, but I think I'm in the clear. Now if only his butting teeth would correct themselves...
