One of our 6 mos old RSLs started acting lethargic about a week or two ago. I've been keeping my eye on her, checking her vent, making sure she eats and drinks and so far all I could say was that she was just walking slowing while the others ran around the yard. Yesterday morning she was noticeably puffed and stood in the corner while the other ate and drank. Her comb had turned darker with the ends crusted over. I checked her vent and while she had poop on her feathers, her vent was clear and a normal color. She was not pushing. This morning, when I threw out scraps of lettuce, spinach and bread, she sat by and watched while the others gobbled up the treats. It was time to check her out. I took her up to the house and washed her with warm water. She has a foul odor coming form her vent. I lubed her up and felt inside her, but could feel only one track - she has a large mass about the size of a grapefruit pressing up against her backend. It had the consistency of an orange or grapefruit too - firm but with some give. What am I dealing with here?