How long does blood in stool associated with intussusception last?

Less than a week: Depends on how severe the intussusception was. Usually after successful radiographic reduction, blood in the stool should resolve within a week. If there is persistent lower GI bleeding, then need to consider other causes (eg polyps, meckel diverticulum, etc) that could account for both problems.

Until it is treated: If you are talking about intussusception in young children then blood may last until it is treated. You should be seen by your healthcare provider and if it is something new and the child is sick then go to the er.

Short time: Onces the intussusception is corrected the bleeding will usually disappear in 24-48 hours. The inner surface of the bowels heal very fast. If surgery for intussusception involves a bowel resection then the bleeding can last a little longer, but is self-limited.