This same exact thing happened to my daughter at age 2, it lasted for about 6 months. I was determined to help her. My cousin's daughter went through the same thing too! This is so common. My doc is great and we came up with a plan that worked. One painful bowel movement can terrify a toddler, and they do not understand at that age that all BM's do not hurt. My doc recommended we use a small dosage of a natural laxative and change in diet. Understanding constipation can really help, research it and learn as much as you can. We used a senna product, when laxatives are used in small doses they act as a stool softener. It sounds like you are doing that. We did not have luck with the chocolate or powders, so we found this really great product at our local drug store...Fletcher's Kids Natural laxative with senna. It is root beer flavored and she loved the taste of it. We gave it to her every morning and evening 1tsp, for about 6 months and then weened it. The reason for this is to increase the number of soft BM's so your child can get over the fear of pooping, in essence you need to convince them pooping is normal and will not always hurt. We also gave her lots of water and pear juice, no milk and limited other dairy products. She ate lots of green veggies and melons, grapes, raisins, we switched out all of our white flour products with whole wheat products. After about a week of this life change she began to poop regularly (once a day), you need to be careful not to cause diarrhea, because that can be painful too. Sticker charts and rewards did not work well for us. We did have a small shoe box on the back of the toilet with small prizes in it and she was able to get one when she had a nice big BM, that worked for a while. But, the best thing for us was the senna and diet change. It is a year later now and she is no longer having issues. I could write more, but if you want more info and more specifics, let me know. I will tell you that I felt like poop ruled my life and my husband would call me the "poop warden" LOL. Hang in there and know that there are ways to help your child through this.