Hello and welcome to HCM, Passage of stools mixed with blood is called dysentery. This condition is painless. The most common cause of dysentery is infection of the gastrointestinal tract. You need to consult your physician for stool examination to look for evidence of infection. Other possibilities include presence of some kind of polyp or growth in the large intestine. If there is no evidence of infection, you need to consult a gastroenterologist for examining the lower GI tract by colonoscopy. Piles or hemorrhoids can also cause bloody stools, however, hemorrhoids are usually not painful. Thanks and take care Dr Shailja P Wahal