21 With Bloody Stool Streaks

Im a 21 year old male. I drink every few days or so, just a few beers. I consider myself healthy, athletic and workout about 3 times a week and walk alot seeing that i'm a waiter. For the past 3 or 4 weeks i've had on/off blood streaks on my stools, not in them- it happens about every other time I poop, which is once or twice a day. It doesn't seem to hurt either, and the poop doesn't look all that unhealthy minus the small streaks of blood. When I have blood on the feces, I get it on my paper when I wipe. I have also noticed that the entrance to my anus gets itchy on some days as well in the last few weeks. No unusual stomach aches or anything though its rather painless, just the blood. I started taking metamucil (fiber) twice a day starting 2 nights ago, and I had a bloody stool tonight too. What should I do? Should I see if the metamucil works? I know of no history of cancer in the family either. Oh, and I don't get it on my underwear throughout the day that i've seen, just on top of the poop every other bowel movement or so.