Can piles cause bleeding?

Yes. Piles are an old term for hemorrhoids and yes, they can cause bleeding, but so can many other diagnoses, including colon polyps and cancer. Get an colorectal surgeon or gastroenterologist to confirm the diagnosis. No amount of bleeding is normal!
Yes. Piles are small collections of blood vessels under the skin near the rectum. They can enlarge in pregnancy and become pretty fragile. If they are traumatized, they can bleed a little. Usually this is spotting or a little blood in the toilet rather than a significant amount of blood. The best way to prevent this is to have soft, formed bowel movements.