hello and welcome;-) any blood in stools needs investagted..possible cause is hemarroids which can be internal and may bleen when having a bowel movement.you may experience itching also and the blood is usually on tissue and not in toilet pan..
constipation is usually the culprit..this can be treated by diet of high fibre, oats and veg along with preparation h if hemarroid pops out and is sore..
If this info is not much help maybe rectal examination from doctor will help along with stool sample..
never take risks from rectal bleeding, either hemarroid or blood in stool...irritable bowel is also another symptom..
hope this helps you.