ckl, I have 2 boys, ages 2 and 4 1/2. My 4 1/2 sounds like your son. He has interests like going through home depot catalogs, or flyers, he has just started to like tv, and now knows what time every show is on throughout the day. We are not potty trained. We were 97 % trained, and then something changed. He now goes only in his pullup. I think someone called him a baby for going potty in his pull up and then we had a big problem. It took me a little while to figure out what was happening. He was running around the house to stop the urges to go potty (bowel movement). Then the next day he would go upstairs, and call down to me and say how much it hurt. I was hurt because I could not help him. He was going once or twice a week. He used to go once a day. He had held it, got constipated, and had a really hard time going. At 4 1/2 we are starting all over and now he is on Miralax. I took him to the pediatrician to check for bowel obstruction, and everything was ok, we just need to have a ton of positive re-enforcement. We actually now just want him to go in his pull up, and we are so excited when he does.

He is at home with me most of the time, but I did put him in a home based preschool, 2 days a week, 2 hours a day. He is doing really well. He has 1 real friend, and some relatives that he plays with every once in awhile. I would like him to have a playdate here at the house with some of his friends at preschool soon. He was born in June, and seems to be very artistic, smart, but maybe a little behind in somethings. I am not sure if it is because I have always stayed at home, and he has mostly been with me. I also have a 2 year old and he is opposite from his brother in many ways. So we will see. I have some of the same worries you do. I think we are going to keep my oldest back and put him in k4 in September. That way he only goes 1/2 day everyday, instead of full day k5. I think for him full day is too much.
I worry but, he is healthy, active, and a lovely child. We are great mothers. Good luck, and keep me posted, we have some things in common.

Kass we have SO much in common! My son is also on Miralax, and had horrible constipation problems as well - in addition to the potty training issues. There was one point where we were having to give him enemas which was the worst. Have you ever talked to a doctor about your concerns? My pediatrician and speech therapist were both not concerned. But just some of the characteristics sound somewhat similar to autism, although both are clearly high functioning and probably just have personality quirks. My son is already old for his grade because of where his birthday falls so will be starting kindergarten in the Fall at age 5, turning 6 that Dec. I'm not worried about academics - he's super smart and advanced in that way - more worried about the social aspect.