Once in a while i will have blood in the toilet after i poop not always tho... i'm also constapated a lot too what's wrong?

Rectal bleeding: Rectal bleeding is never normal. It sounds however that your's is caused by constipation and probably large stools causing an irritation and "inflamation" of your lower intestines if you see 'red blood" in the toliet. Increasing fiber, fluids and maybe even a stool softener can help. However, even though it is probably constipation or hemorrhoids, you still need to see a GI dr. To get an eval!