Hi moose. Welcome to the boards. When you have to go, is it diarrhea or formed? If it's diarrhea, then you may have a gall bladder disorder where too much bile is being secreted during the digestive process stimulating urgency and diarrhea. If you are having "D" do some web searches on bile salt diarrhea & Habba syndrome to see if the symptoms fit you. I had chronic and immediate "D" either during or after meals after my gall bladder was removed. I now take Colestid which has helped me have formed stools. The urgency may still be there, but at least I can get to a bathroom in time. Sometimes people with their gall bladders intact will still have frequent urges after meals which has been identified as Habba syndrome. There's not a lot of info on it, but I found a few helpful articles during a Google search.
If you're having formed stools after eating, this may just be the way your system is. Sometimes the act of eating, will stimulate digestion and elimination. If this is new condition for you and if you're losing weight because of it, please see your doctor. It's important to rule out anything serious.
Good luck and keep us posted,