@jmmb , yes Nitro is commonly used for chest pain like angina, it also works for intestinal angina. MALS constricts the arteries by compression of the ligament. Most people, once the ligament is released are symptom free, however some people's arteries have "memory" of the constriction and even after bypass can cause problems. In my case my arteries look open and flowing upon all tests, but I believe at times, mainly after I eat or exercise my arteries vasoconstrict so much that they go into spasm and cause pain. Nitro, a vasodilator opens the arteries up, and the pain goes away. Unfortunately your body can get use to nitro just like it can any medicine. I try and use it sparingly. Does that make sense?? What has worked best for me is Tramadol before meals, but doctors are not comfortable prescribing this medication because of its opioid effect. This makes it a challenge for me and my doctors. There is a combination of things that are contributing to MALS pain, another is the ganglion nerves... there is just not an easy fix.