sounds like hemerroids. Blood in your stomach comes out black. Hemerroids are normally created inside the anus until we strain during a bowel movement and then they can protrude outside. Preperation H depositories work great. Good luck.
This can be because of internal haemorrhoids. This is a painless condition..At such a young age, this can be hereditary when coupled with sedentary life style. I know, may be u r a bit embarassed to go to doctor with this situation, but it's ok to go to ur family doctor and make sure of ur condition..it can even be a infection. Tell ur parents first. There's high chance that they have had the same situation .Internal haemorrhoids is not much of a problem..it is very common..This is one of the very early stages. and completly curable..Keep a check on what u eat ...avoid pickles and heavily spicy food. Eat more of fruits. This is to decrease chances of constipation which can make the situation worse.ont spnd too much tym in th toilet. Dont panic at all. My nighbour had the same condition. She is absolutely fine now. Get well soon