How do you know if you have internal bleeding or it is just hemorrhoids bleeding?

Hi ,i do have hemmorodids , i am 22 and i take coumadin, no injuries, also only the end of my poop as blood on it . it is not in the poop.

internal bleeding:
could be fresh red blood or dark to black in color, depends if the source of the bleeding is away from the rectum (stomach, small intestine, etc) so it takes time to reach the rectum and it gets digested by the acid of the stomach and gets clotted.
if it is from hemorrhoids, it would be painless, fresh blood, with and/or after defecation..
you need to provide more detailed history of the problem, onset, with or without pain, other symptoms (drowsiness, loss of weight, appetite..etc)
your age, smoker or not, history is very important to diagnose your case, se seeing your doctor is important, it could be as simple as hemorrhoid or as serious as malignancy..