Bright red blood on the toilet paper or surface of the stool is often from haemorrhoids (piles) or a small tear, especially with constipation. However, blood can also come from inflammation, infection, polyps or bowel cancer, so it should never be ignored, even when it seems minor.
Black, tarry, foul-smelling stools (melaena) suggest bleeding higher up in the digestive tract, such as from a stomach ulcer, and need prompt assessment. Book to see a doctor for any rectal bleeding so the cause can be found, particularly if you are over 50, have a change in bowel habit, weight loss, or a family history of bowel cancer.
Seek urgent care or call your local emergency number for heavy bleeding, black tarry stools, vomiting blood, fainting, severe abdominal pain, or signs of significant blood loss such as a racing heart, dizziness and pale clammy skin.