I feel really sick AFTER I have a bowel movement -- I get really shaky, nauseous, sweaty, chills, and start having a hard time hearing.?

Blood pressure low. If this only happened once, don't worry about it too much. If it happens every time, it sounds like your vagus nerve is overactive and it is causing all of these things. Make sure that you don't get constipated and have to strain to get it out or have a lot of pain. If it keeps happening, you need to see a clinic and particularly to get your blood pressure checked. And always get UP SLOWLY.