Day and nighttime potty training are different.
For the daytime issue, it sounds like your ds can control the wetting in some settings, so I'm guessing there's not a medical reason for his wetting. If you want, you can get an evaluation from your doc to rule out urinary infections or anything like that which may make it harder for your ds to stay dry. Constipation can also cause more wetting accidents since it puts pressure on the bladder.
Next, I understand why you let ds have the diapers, but since it's not a solution that seems to bother him, I think you need to take them away from him again. He needs to experience discomfort as a consequence of his wetting. You can get plastic pants to go over his underpants to minimize messes but still keep the wet undies against his skin. You may want to get some thick training underpants that hold more moisture to help reduce messes as well. Hopefully, sitting in wet clothing will make your ds uncomfortable enough that he gains an interest in using the toilet more regularly. When your ds is wet, he needs to change his clothes himself, so HE gets to experience the unpleasantness of handling urinated undies and clothing.
If you thought it would help, you can get a watch with a timer or that vibrates throughout the day to prompt your ds to toilet regularly.
As far as nighttime bed wetting goes, first the body must develop a hormone that signals the kidneys to slow urine production while the body is asleep. Without that hormone, the body produces too much urine for the bladder to hold. Once you see signs that your ds is wetting less at night, then you can limit fluids before bed and take him to the toilet once during the night to help train him to be dry overnight. Most doctors don't consider bed wetting a problem until a child is 7-8yo, and even then there's not a lot the docs can do except perform a physical exam to make sure there's not a physical cause for the problem, or write a prescription for a synthetic version of the hormone to slow urine production. Just let your ds have a pull-up, and don't worry about it until ds body is ready.
It kind of depends upon how you want to handle it. If you feel he is only having accidents during the day because he doesn't want to take the time to actually go to the bathroom you can make it so it takes less time to stop and go potty than it does to clean up after an accident. If you feel he needs time then continue with the diapers or pullups (I'd use the training ones that let him feel wet) or training pants with a cover during the day. One of the pp was right on about night time and day time training being different. Nighttime is something that will only happen once his body is ready. So you can't compare the two and you can't really night train. They do it or they don't according to their body's readiness.
What ever you do, do not get upset and give into your frustration. This is something he needs to learn to do on his own and is an area he has more control over. You do not want to turn this into a battle. If he has an accident, continue to be matter-of-fact about it regardless of how you decide to handle it.
If you decide that you want to "push" it because you feel he really knows what to do but is just being difficult about taking the time, have him clean up the mess. He changes out of his wet clothes, he wipes himself down, he changes into new dry clothes and cleans up any mess that made it to the floor. The wet clothes he can put in a bucket or in the bathtub for you take care of later. If you want you can have him help start the washer. Basically you want it to take longer to stop and clean up after an accident than what it would take for him to stop playing and go use the bathroom. It takes away the argument of not wanting to stop playing to go to the bathroom, because they realize that they would have more time for playing if they just stopped for 2 minutes and go instead of having to spend 5 or 10 minutes cleaning up after an accident. It may take a while for it to sink in but it will especially if you are matter-of-fact about it and stick to making him do the clean up. "I know you'd rather be playing but you need to clean up first. Lets hurry so you can get back to it quicker."
After a few accidents you can ask him if there is something he thinks you can do to help him. Does he think it would help if you set the timer? What if you reminded/ask at certain times during the day? Let him take the lead but offer some suggestions. He needs to decide that he wants to do this but you can help him.
Hi! This is my first post here, but it sounded almost EXACTLY like my life, so I just had to comment! I have a 5 yr old stepson who lives with my husband and me, and he is a daytime wetter. He never wets the bed at night, only during the day, and he does it wherever. Kindergarten, daycare, after-school care, my parents house, husband's parents house, our house, grocery store, you name it. I read an interesting article that stated that, according to the symptoms he exhibits, he may have ADHD. I know, I know, blanket diagnosis, but it was interesting. He won't stop playing to go to the bathroom, or stop watching a movie, or get up from class, or ask in a grocery store, but he wakes himself up in the night when he has to go. According to our doctor, that definitely sounds psychological, not physiological! We have an appointment at the end of the month to take him to a pediatrician, and we're also signing up for some counselling for us all - to try and get to the bottom of it. We've put him in pull-ups during the day, but he's totally cool with it... he sees it as a free pass to go without getting his pants wet. :P And it also doesn't bother him one little bit to sit around in wet underwear or wet pants, he's completely fine with it.
You can kind of get the daytime home wetting under control, because you are there to ask every 1/2 hour, every hour, etc, "do you have to go to the bathroom?" (jake's response when he does have to go is "ummm... I'll try!"), but it's hard when your child is being watched by someone else. I know the daycare/after-school/K teacher try to ask him, but ... they've got several other children to supervise, and sometimes, it slips through the cracks. This is Day 2 of no accidents after a week and a half of accidents at least once a day, so we're hoping that he'll stay on track this time.
Good luck with everything!!!!!
My DS turned four in December still has accidents.