My son is 7 years and 9 months old ,
Need some details...
I would like to know if this was one time occurrence or does it occur often?
Is he able to pass stool without problems? Or is he constipated?
Fresh blood with stool is often from the lower intestine (rectum) and it is usually due to minor trauma secondary to hard stools. Sometimes a fissure in anus may cause the same. It shouldn't be concerning as those heal spontaneously with extra fluids and fiber rich diet. But if the problem is a recurring one, it would be worthwhile to get it looked by his doctor.
Hope this helps. Let me know if you need clarifications.
Try the above mentioned options...
As and when stool becomes hard, it becomes hard to pass out and he might have to push harder. This will induce some trauma that may bleed. I suggest you try above mentioned treatment options (increased fluid intake and fibre rich diet) and see if it gets better.
Hope this helps. Let me know if you need any other clarifications.