I have been having digestive problems for a while: stomach pain, constipation, bloating. When my digestive problems are at their worst, I feel dizzy. After a large bowel movement after being constipated I will feel dizzy too. My doctor said that this is because of pain. I don't know if that is true. I am not usually in severe pain when I am having digestive problems and dizziness. There is usually a little bit of pain, but i've had much worse pain other places in my body without getting dizzy.