Probiotics, even a little occaisional yogurt n food may help with bacterial balance for the diarrea. ACV and dish/rainbarrel cleaning too. Cecal poo is yukky and would continue now and then on a regular basis.
She might have split her oviduct inside and possibly had internal laying...and could have retained and started an incubation. if so, there would be bloating and other eggs inside to create health problems. I doubt a burst oviduct before the calcium depositing end can actually benefit the bird - unless shelless, and somehow her body can assimilate or pass the material - but my Wiley might be doing just that...since December somehow. Will know better this Spring.
Egg peritonitis or heart stopping from pressure would be likely outcomes., as ovulation continues. You'd see some weird ones if she's passing some outside from a damaged/partly healed uterus. I had such a thing happen - with my BJG Wiley - she had an egg song that recurred a lot during sick bay week, and began passing narrow calcium pelleted material, alternately from poo, and I've seen one shelless egg deposited on top of the pellets. As long as it doesn't make her sick or kill her, we are happy to keep her and if she becomes Broody we'll give her a chance to fulfill her Chickie-mom potential .Hoping she will be a gentle protector o the new batch of chicks i hatched 2 weeks ago- when they are ready to go outside. Will try to post a pic from a camera of the oviduct material she has passed occaisionally since being sick/eggbound late November first week of Dec.
Salpingitis is one of the reproductive tract diseases to research for lash egg pictures. There are also rubber eggs that are not pus masses...add calcium for those. Stop or reduce use of light if several eggs are coming at once on the poo board from young birds. You may find help under vent gleet also. Check all the basics and be sure she gets her fair share food of food/water if low on the pecking order. More than 1 feed station, and 1 always available helps this. If she's sickly and not able to resume normal laying in spring many farms would cull. Rehoming to someone with an older bird who needs a companion may also be an alternative. GL.