Hi! When I use the bathroom (#2), when I strain.. I have a horrible pain on the left side ofy head. What causes that? I also have been having horrible non-stop gas. In the last 12 months I have gone to the doctor & neurologist for testing due to headaches in general and nothing. Very healthy. Now months later while using the bathroom, this new head ache strain symptom comes along and has been bothering me DAILY for about 2 weeks or more. Help!