My toddler was using the potty frequently when he turned about 2.5 years, then after Memorial weekend, he suddenly stopped going. He seems to hold it forever and is very stubborn. I haven't had him go to the potty since the end of May. Is there a way to retrain him to use the potty on regular basis? He is almost 3 now.
It is actually relatively normal to revert a little. Try not to get upset or punish, accidents do happen and it is developmentally appropriate for him to be more interested in play time right now. They get busy and want to play and think they can hold until something more boring is going on. If he is at home with you it would be pretty easy just to have a "pit stop" every hour to hour and a half as part of your routine. Be upbeat and positive about it AND when you decide you need a pit-stop talk about that too. "Wow, I have to go potty right now. I wish I didn't have to because I like reading stories with you, but I'd better go so I don't have an accident. I'll be right back" or, "Hmm. . . before I get in the car I think I will try to go potty so that I don't have to later while we're driving. You should probably try too. Do you want to try before me or after me?"
If he is at preschool - most of the good ones work regular potty breaks into the schedule anyway.
He is likely to be reluctant, but you can reassure him that after he has tried, he can go back to playing again. Then praise him for trying when he does sit down and give it a try. If he absolutely refuses, I wouldn't force it. I liked to point out to these kids, how much MORE play time they miss out on when they have to "get cleaned up and changed" because an accident instead of just using the potty in the first place (natural consequences you know). If he still won't try, let him have the accident and then while he is getting cleaned up be really slow about getting him dressed again while you say something along the lines of, "Darn, what a bummer you have to spend all this time getting clean again. I'm sorry that happened, what a bummer you didn't try to go earlier, you could be out there playing right now. Darn". Again, the idea is not to stress that the accident was bad, but that he might have avoided it if he'd made a different decision earlier. No punishments and that is all, enough times with this message he'll eventually get it.
Once in awhile, this kind of a "revert" can be because of something that stressed or continues to stress out the child such as a move, death of a family member, divorce or even something that seems pretty innocuous to us but may not be a big deal to him like a change in baby sitters or a friend moving away. If you suspect this might be the case, talk to him about it. Ask what he thinks (he may not be able to really tell you, but ask and listen to his response anyway) be patient, allow the backsliding for a little while and make sure you are giving your little one lots of reassurances and attention. After a week or two, start what is outlined in the paragraphs above.
Either way, with your patience, understanding and caring support this too, shall pass.