How to manage IBS symptoms?

Hi doctor,

I have been diagnosed with IBS by a few doctors, including yourself, when I submitted an inquiry on this site a couple of years ago. I would like to inquire about the two troublesome issues:

1. Excessive gas. It does not happen every day, but there are times when I have problems with it all day. Simethicone and charcoal capsules do not work. I have documented what I eat and have not noticed any patterns of foods that cause gas. Are there any strong prescription medications you can suggest that stop gas?

2. Stress triggers my stomach to start churning, and at times, it results in me using the bathroom. When I have to drive a long distance, I worry about my stomach, which results in me using the bathroom three to four times. Another time, my mother had to be taken to the ER, which resulted in me using the bathroom often.

Are there any medicines that can stop you from going to the bathroom or slow down the digestion process?

Please help.