The most common causes of blood in stools are hemorrhoids and anal fissure that cause tearing in the lining of the anus due to forceful bowel movement .Intestinal infections like ulcerative colitis, inflammatory bowel disease, diverticulosis, Crohn’s disease are few other possible conditions which can lead to blood in stools. Colon cancer is a rare but serious cause of blood in stools. It is best to seek medical help and get him examined. A rectal examination and tests like flexible sigmoidoscopy and colonoscopy may be needed. Do keep us posted.