Sorry to hear. Can you treat the symptom of constipation? A cup of grape juice works for my son but there are stool softeners and other tricks to keep things moving. But the issue of vagus nerve problems is such that you should follow up. If you do indeed have weakness, they may do nerve therapy? But many who have that also have issues with their heart and other areas. Any other symptoms?
Let me know how it goes and if you are able to overcome the issue. :>)