Hi,
Welcome to health care magic,
Blood in stool or bleeding during defection could be due to piles,fissures, fistula or rarely any growth in
rectum etc.
It will be quite rare that tearing of rectum might cause blood in stool but tearing of rectum linings is rare.
First you need to be examined around anus and per rectum by surgeon to rule out above possibilities.
Meanwhile,you can take below treatment for symptomatic relief.
1) Take quinolones antibiotics with antiprotozoals,
2) Anovate or Dobesil cream or ointment to be applied over anus after defecation,
3) Hot seitz bath,
4) Sit naked in hot warm water for 15 minutes
5) Avoid alcohol,
6) Avoid oily and spicy foods.
So,it would be better you
consult general surgeon who will do thoroughly clinical examination with relevant investigations like
colonoscopy to detect the exact underlying cause.
Regards,