Would could cause nausea during a bowel movement?

Reflux: there are many causes of this phenomenom. most common would be reflux. as we exude pressure with a bowel movement, we increase pressure in our stomach which can splash acid up on our esophagus triggering nausea. sometimes Motrin or advil (ibuprofen) can exaserbate this process

MANY CONDITIONS: Nausea can be due to many different causes and I see you are taking Advil (ibuprofen).Motrin and Acetaminophen.Motrin and Advil (ibuprofen) are same drug IBUPROPHEN and it can cause nausea/vomiting and other GI Symptoms Orher causes are Irritable Bowel Syndrome,and other GI Disorder You should get yourself checked as you also have headaches,fatigue pain etc.