I had constipation n some time watery stool on n off last 3d I had blood in stool notice drops if blood as well as irritating pain sitting is issue?

Anal pain. You most likely have hemorrhoids as a result of chronic constipation. Eat more fiber, drink lots of clean water. See your family doc.
Hemroids . Seems most likely that you have irritated your hemroids, which are veins inside of your anal canal! If this is just a one time occurance then you can buy OTC creams that will make you more comfortable, also sitting in warm water in your bathtub can help! If however this continues it is very important that you seek a more thorough exam including a colonoscopy! This could be the first signs of se.
Bloody stool. Sounds like hemorrhoids..... Add fiber to your diet.... Monitor it for a few days.... If it doesn't go away, see your doctor.