(((Kelly))) It can be so many things. I haven't been able to tolerate dairy products for quite a number of years now - cream cheese being the worst. I also can't tolerate a lot of fat in my diet anymore and if I eat too much I certainly regret it either later on that day, during the night, or the next morning. It doesn't cause IBS symptoms, just pain.
Like you, I don't if it is MS, age, something else, or a combination of things. I just know which foods I need to avoid and the list seems to be getting larger.
I did read an interesting paper by some medical student about leaky gut syndrome and MS. I wish I could find that link. I just checked and did see it. I am hesitant about some of the links that came up when I googled it. I would rather read through the scientific studies that some random site promoting pills to help.
I 1st read about it in the ALS forum:
http://neurotalk.psychcentral.com/thread33616.html