I've had constipation for a while i think its chronic constipation i get it sometimes with no blood and small amounts of strain and sometimes bright red blood in bowl or on paper and recently i had blood 2 time in row could that be a fissure tear????

Yes, it could be.: A teen or young adult with constipation needs to be sure there is no other disease causing it. If constipation is just due to slow movement of the food and poop through the gut, things to try are vegetables, prune juice, prunes, fiber-plus-water, polyethylene glycol, Senokot or other senna, milk of magnesia, etc... Make a symptom and "laxatives" diary for the doctor, who can assess and help.

Constipation: Constipation can certainly lead to an anal fissure. It is also rather time consuming to resolve constipation. Work with your doctor on increasing fiber in your diet, increasing water in your diet, and using laxatives such as Miralax (not chemical/drug based laxatives) . The process should take a few weeks and you will need to continue diet modification. This will reduce fissures.