What can cause rectal bleeding ?

Possibilites: Include hemorrhoids, diverticulosis, colonic polyps or cancer, an arteriovenous malformation (such as from osler weber rendu), an anal fissure, ulcerative colitis. Get checked!

Numerous: From hemorrhoids, fissures, fistulae, inflammatory bowel disease, diverticulosis, to polyps, tumors benign or malignant. Also meckel's diverticulum, and upper GI sources such as ulcers and gastritis and tumors benign or malignant. No bleeding is normal. Get properly evaluated by a GI doctor or colorectal surgeon or at least by your primary care doctor. Do not ignore rectal bleeding.

Many: Depends on a person's age and medical conditions. The list of possibilities is long. Fistula, hemorrhoid, fissure, cancer, colon polyp, colitis, rarely from stomach ulcer, etc. Would need to have an examination with your doctor.

Lots of stuff: Hemerrhoids, cancer, trauma, diverticulosis, ulcers, meckels diverticulum, a-v malformation, infection and more. I once had a "vampire" who presented to the er with blood in his stools from drinking blood from the hospital blood bank.

Many possibilities: Hemorrhoid, anal fissure, anal fistula, draining peri-rectal abscess, colitis, colon polyps, bleeding stomach ulcers, bleeding colon diverticula, colon vascular malformation, colon or rectal cancer, and maybe others.

Many things: Many things can cause rectal bleeding. The one we worry about most is cancer. Anyone with rectal bleeding needs to see a doctor to evaluate it further.