Erin - It all depends. How much blood? Was there mucus as well? Were you straining to have a bowel movement? Straining can certainly cause a little blood in your stool. Keep an eye on it and if things get worse, call the dr or go to the ER. There maybe something else wrong other than constipation or in addition to the constipation. Also, keep in mind that some of the stool softeners/laxatives take a day or two to start working. An enema would be more immediate. A colonscopy prep, well...., it works and sometimes fast.