It is worth noting that while taking medications such as iron supplements or eating lots of beetroot can change the color of your stool, it is recommended you visit your doctor if you notice red, plum or black-colored stools. Other causes of rectal bleeding can include: 1) Hemorrhoids (piles), potentially painful varicose veins that bulge from the rectal wall. They can look like small grapes and sometimes protrude outside of your anus. Bleeding is usually bright red and characteristically seen on the toilet paper. There can be quite a sudden, small bright red bleed if a hemorrhoid bursts, with lighter bleeding afterwards. 2) Anal fissure - this is a small tear or open sore in the lining of your anal passage. The bleeding is usually bright red, but doesn't typically last long. 3) Diverticula - these are small pouches or bulges that form in your colon if you have a condition called diverticulosis. The pouches sometimes have weak blood vessels in them that can burst, causing painless but often heavy bleeding. The blood is usually bright red and warrants prompt medical attention as there can be significant blood loss. 4) Inflammatory bowel disease (such as Crohn's disease or ulcerative colitis) can cause bloody diarrhea. 5) Bleeding disorders such as hemophilia can cause profuse bleeding in some of the above situations. 6) A bleeding gastric (stomach) or small intestinal ulcer - these can be life-threatening very quickly due to the amount of blood lost. The blood seen rectally is typically dark and sticky. 7) Non-steroidal anti-inflammatory drugs such as ibuprofen or diclofenac can cause ulceration and bleeding in the upper digestive tract. 8) Endometriosis.
