I have the equivalent of gastroparesis (as explained by my gastroenterologist) in my oesophagus... my stomach is ok aside from inflammation, and I have IBS the lower half. So quite often driving for me especially in the mornings is quite painful. I've just eaten breakfast though and that may be why as my digestion is slower than normal. People may say well eat breakfast early, etc... doesn't work as I have a tight time frame from time of getting up, taking my meds that have to be taken with food, getting dressed, and heading to work. But I usually don't have issues with my blood sugar... although no doubt I may spike on my way to work as still digesting.... but I feel fine other than the pain I get.