Yes muscles are a big part of things too, you're right monty. If we carry our stress reactions there.. that can upset the system too! When my ilia is out, I suffer greatly, since the muscles contracture in the lower torso.

On a day to day basis I must eat a green salad daily. (Add to the muscle, nerve probs, I also take demerol for the chronic pain...and that constipates by itself.)
There are many good foods that add ruffage without exacerbating the problem you may be having. Finding out what works for you and what doesn't is key, and I agree, keep a food diary until you figure it out!
(Oh yes Jan! A spare set of clothes in the trunk... with wetnaps.)