Your child has entered that age when he has joined school. He has grown self-dependent and is able to use the washroom on his own. But there are certain things which need to be taught correctly.
What you need to know
The use of tissue has to be taught to the kid so that he can work on his hygienic habits. Ask the kid to wipe with the tissue under your supervision. Let the kid practice it for a few days and you must give a final wipe at the end to make sure the job is done.
What you can do
Once the kid perfects this task then let him help himself. To check this, keep an eye on his laundry. If the underwear is dirty then it means the training needs to be perfected. The next step is to teach the kid to dump the tissue in the bin after wiping. Such habits are very important for the child to grow into a clean person.