You have alot going on here and need to see a doctor about this to get it resolved.

Red blood in your stool is usually associated with bleeding in the lower digestive tract or from hemorrhoids while black or tarry blood is associated with bleeding ion the upper digestive tract. Severe heart burn or acid reflux can result in blood in the stools but they would have a black or tarry look. 

Many things from appendicitis to kidney stones to simply constipation can cause lower right abdominal pain.  

If you have constipation and are straining to move your bowels you could end up with a hemorrhoid which is causing bright red blood to show up in your stools. You'll have to see a doctor, though, to find out what is going on. Good luck!