Hello. I'm Dr. Christensen.
I'm sorry your nephew is having problems. His symptoms are worrisome. Rectal bleeding
at any age should be taken seriously. Although hemorrhoids are the most common cause of such bleeding, your nephew's symptoms are more suggestive of inflammatory bowel disease
(e.g., ulcerative colitis
, infectious diarrhea
(e.g., E. coli or C. difficile) or a bleeding ulcer, all of which can be serious or even life-threatening. I agree that your nephew should see a physician as soon as possible; his ongoing bleeding may have already made him anemic.
I hope that answers your question, and I hope your nephew does well.