Thanks for posting your query in HCM.
No, being constipated is not part of G6PD. You need to be sure that is it really constipation
What suppository are you using ie any medicated or plain glycerine .
Its not a good idea to use any suppository daily.
you can simply try to give him more fibrous diet eg fresh juices of fruits (not the packed ones). Try to add more sugar in his milk and food. Use of high sugar will also result in soft stools which will pass easily.
If you are using medicated suppository it will clear the bowel , so it will take some time for the bowel to fill up with some stool hence causing rebound constipation.
Please consult your family physician regarding this.