How is your hen doing?
Calcium supplementation is regularly recommended for cases of dystocia, prolapses, or egg binding to help enhance muscle contractions in the oviduct and to better strengthen eggshell formation. For supplemental calcium, you can use one calcium citrate + D3, or Calcium gluconate 23% given at 0.2ml per pound, orally. Tums can also be used, anecdotally, I have given around a pill at a time, but the tums form calcium carbonate, does not stay in the system very long, therefore, the other supplements may be preferred.
In addition to calcium supplementation, ensure the hen is hydrated well, to further ensure that, you can offer sugar water or an electrolyte such as Gatorade, or Sav-a-Chick.
I would not switch her over to cracked corn, she should be on layer feed, cracked corn will help induce the problem from reoccurring due to the several minerals, and vitamins it lacks. If the prolapse reoccurs, try using something like DMSO, or preparation H on the tissue, to better reduce any edema going on. If it continues to prolapse, it is likely she has an egg further up the oviduct creating pressure on the tissue, in which case ovocentesis, and bilateral sutures placed on the vent may be needed.
