Hope you're not in much pain.
Usually fissures occur due to large sized hardened stools that which are hard to defecate. It occurs because of consuming less water and lacking of diet fibre in your diet. The hard stools while passing out will rupture the tissue of the anal sphincter internally. Being one of the most vascular part in our body the anal sphincter will bleed as long as the fissure is treated surgically and some times the bleed will be continuous and make your hemoglobin levels come down so I advice you to careful with and you need to observe the bleeding. You need to take 2-3 liters of water and along with that you may take carrots, cucumbers, leafy vegetables, banana, okra, butterflies, beans as your diet so that you'll get the Abundant fiber and which helps stools to pass out easily.
But before that you need to consult a doctor personally to get you condition treated.
Surgery will be the permanent cure and it's short and painless surgery.
Take good care of your health.