There are different causes for blood in stool
.1. Hemorrhoids, 2. Fistula; 3. Fissures 4. Causes higher up in the colon, like diverticula.
My recommendation is , get the anal examination(using a scope called anoscope). Through this examination surgeon will see any thing abnormal , like hemorrhoids in Anal canal
If nothing is seen in anoscopy, you may need Colonoscopy
Because all these are surgical problems. Treatment depends on the cause. Medicines will not cure these diseases.