Hello, i'm 17 years old and every time i'm done doing my business right well i've noticed that i'm bleeding from my anus/rectum area this started abou?

Anal bleeding: Check for hemmorhoids. Do you have constipation? That can cause hemorrhiods due to excessive straining during BM .Avoid hemorrhoids by drinking about 2-3 liters/ day water /gatorade, juices ,milk and eating fiber lke a cup of oats, lentils,barley brown rice /day Also consider diverticular bleeding which is rare at 17 , polyps or inflammatory bowel disease