J.G.
T.,
This can be so frustrating! My son went through something similar at 3.5, too. From what I've heard and read and experienced, 3.5 is a very difficult time for preschoolers, and they often have some potty training regression. A few things helped us get through this stage:
1. Positive reinforcement -- sticker charts, prizes, praise, whatever works for your family. That may change weekly, so always be ready to introduce something new.
2. Stay away from negative reinforcement -- taking something away is not going to help.
3. When an accident happens, try not to show any emotion. Just be very matter-of-fact about cleanup and say something like "Its ok, it happens. Maybe next time." I know that inside you may be angry, frustrated, or even blaming yourself (I know I did!), but try very hard not to let these feelings show. Yelling will definitely NOT help the situation!
4. A scheduled time to sit and try to poop. For us, every night after dinner our son would sit on the potty, and we would read from special books that stayed in the bathroom. We found that books of poems worked well, so that when he finished we weren't interrupting a story. At 4.5, our son still has a scheduled time. We have phased out the books, though.
5. Look for any changes in her routine or in her life that might have affected her (subconsciously) in some way. A new teacher at preschool, cabin fever, giving up a nap, a new dinner time, anything that might seem inconsequential to you may be affecting her.
6. Whatever you do, don't let this become a power struggle! I know that is difficult, but if the potty issue becomes a battle of wills between parent and child, the issue can escalate. (I know this from experience!)
7. Check with her doctor. It is possible that the stool softener is causing problems.
8. Read the book "Your Three Year-Old: Friend or Enemy" by Ames & Ilg. I got a copy from Amazon. It will help you deal with all of those inexplicable and frustrating behaviors that manifest at this age.
Good luck! I hope you find some answers here!