When there is blood in stool, the color depends on where it is in the digestive tract. Blood from the upper part of the digestive tract, such as the stomach, will look dark by the time it reaches exits the body as a bowel movement. Blood that is bright or dark red, on the other hand, is more likely to come from the large intestine or rectum.
Conditions that can cause blood in the stool include hemorrhoids, anal fissures, diverticulitis, colon cancer, and ulcerative colitis, among others.
Eating beets can also temporarily turn stools and urine red.
Blood in stool doesn't always appear bright red. Blood may be also present in stool but not visible, called "occult" blood. A test called the Fecal Occult Blood Test is used to detect hidden blood in stool.
More fiber. I used to be fiber different and this would happen to me, but I wasn't constipated. So my doctor said thats it's weird that I'm not constipated, but I need more fiber. It worked, there are pleantt of natural, high fiber foods out there. Also, drinks lots of water.