Here is a thread where this poor sweet woman treated her hen with every antibiotic in the world, but didn't help. Her poop pictures run the gamut of EYP for weeks and weeks. https://www.backyardchickens.com/t/839243/is-it-a-bad-sign-for-an-internal-layer-egg-yolk-peritonitis
Two inches is about all you need to go until there is mild resistance. Many report that they can feel tumors with a cloacal examine. At 3 years she could be suffering from egg yolk peritonitis or internal laying, especially if you have noticed any soft shell or broken eggs, or she has not been...