Potty training

Is anyone out their potty training their toddler? I had my 2 year old all trained and suddenly she started, what I thought was regressing. The doctors seem to think this may be due to a few very painful stools that she had. Instead of thinking her poop hurt her she may think the potty hurt her. Now she is holding it in and having “accidents” all the time. I need to now make her understand that the potty is not hurting her at all and it’s safe to go there. That should be fun!