Well, as many have pointed out, bedwetting is pretty normal, especially at 5 years old. I've read that over 20 percent of 5 year olds are not consistently dry at night. There are a lot of factors that go into a child being able to stay dry -kids being deep sleepers, a family history of bedwetting (if one or both parents was a bedwetter, chances are your child will too) and the body's ability to produce enough of a hormone that tells it to not release urine until a child is awake. Some kids of course also have small bladders - a 5 year old's bladder is very small compared to an adults, yet they generally sleep longer at night than an adult! That's asking a lot of a child to stay dry.
Obviously, all kids develop differently, too. Some naturally stay dry sbefore others. Others are dry and then begin wetting again, and still others have never been dry at night. Several years back when he was 5, my former stepson was a bedwetter. My ex-wife brought it up to his pediatrician who made the following recommendations (and I am no doctor, this is just what he said):
1) During the day, when your child has to go potty and the urge is strong, make them "hold it" for a few minutes before they go -start with just a minute or two, and then gradually increase the time before they actually go, up to 5 minutes, more if your child can hold it. This helps to stretch and strengthen the bladder muscles.
2) DON'T restrict fluids at night, just the kind of fluids he's drinking. He said this goes against what people often think they should do. But, the goal is for your child's body to be able to get through the night dry or wake the child up when he has to go, which means it has to be able to hold a full night's worth of pee. It can't do this if the child hasn't had anything to drink for hours. He said to stay away from things like caffeine or milk before bed (which can irritate the bladder in some kids, apparently) but juice, water, etc. were fine. Again, gradually over time your child's body will learn to either hold it all night, or give them the sensation to wake up to go.
3) Make sure the child isn't constipated. Apparently, children who withhold or have constipation issues are more likely to wet the bed.
4) Don't make a big deal of it. Use a diaper or pullup or goodnite to save yourself the hassle of laundry. Your child isn't alone with his bedwetting, it's just that parents don't like to discuss it when the likelyhood is that there are numerous kids your child's age or older who also wet. The more you act concerned about it, the more concerned your child will be. If you don't treat it like a problem, neither will they! I found this out when the kids on his soccer team (who were all 5-7 years old) were bragging to one another during a game how much they all wet the bed and comparing who wet the most!

There must have been five or six kids talking and ALL of them were bedwetters! The parents looked a little embarassed, but the kids were all fine with it.
Now, I will say even in my stepson, who took medication at night that made him drowsy and even with the constipation issues he had, by doing what the doctor suggested, in less than a year he was starting to stay dry -and this from a little boy who had never had a dry night in his life. I'd think a child with no constipation issues and not on medications who have even better success.