Yous son has been diagnosed as having chronic anal fissure. If his bowel movements are normal, soft, and painless, still on and off passing blood in stools, it would be good if he gets a proctoscopic, and if required a sigmoidoscopic examination to rule out ant rectal polyps. These could cause fresh blood in stools on and off. Please consult a gastroenterologist. Alter the examination doctor can advise the proper management. If there is a rectal polyp, it can easily be removed at the same time of the examination and sent for histopathological examination. Of-course it is good if he takes adequate amounts of fruits, vegetables, fluids and fiber content to keep his stools soft.