It is important that you take your child to see his pediatrician to help you with this. The first step is for him to be examined, to make sure there is no sign of a physical problem. The next step is to clean out all the stool that he has backed up inside. This is usually done with stool softeners, lubricants like mineral oil, or laxatives, over a one or two week period. Your physician can prescribe them if necessary. Often, a child will continue to take mineral oil after the stool is cleaned out, to keep the stool soft, and prevent the problem from recurring. The other important step is to have your son sit on the toilet for at least ten minutes, twice a day, every day, usually after breakfast and after dinner, even if he does not feel like he has to go. This is to help him empty his bowel completely on a regular basis. You may need to give him some incentive to make sure he sits for the full ten minutes (like a sticker reward chart, or having a story read to him while he's sitting). With the proper encouragement, and avoidance of punishment, most children will respond quite well to this type of approach.
Q
My son is six years old and has a problem controlling his bowel movements. He soils his pants at least once, maybe three times a day. He seemed to master potty training at the usual age, so this is something of a surprise to us. We have noticed that he is reluctant to stop whatever he is doing to go to the bathroom. What can we do to help him through this problem?
A
The problem that you describe is called encopresis, soiling the underwear with stool, and it is actually a very common problem in school-age children. It is estimated that one in 25 children have it at some point in childhood. Usually, there is no underlying neurological or intestinal problem, and children are otherwise healthy. It can be precipitated by some sort of stress, and the problem usually starts with an episode, or episodes of constipation. Because it hurts to push the stool out, a child starts to hold the stool in and avoid using the toilet. They can then get into a pattern of holding the stool in. Over time this causes the lower intestine to get distended, and the rectum can no longer sense when it's time to go. There is usually a lot of hard stool in the rectum, and quite often, soft liquidy stool from above will leak out around it. Many children truly do not realize that they have had an accident and do not smell it.