If you have had a vagotomy, taking Nexium is not advised, A vagotomy reduces acid production and the Nexium also reduces acid production. My advice, having gone through the same surgery ,is to stop taking the Nexium,which by the way is not recommended for use more than 14 days. Take a fiber supplement mixed with water and a teaspoon of cider vinegar before every meal . If you should have occasional acid stomach symptoms, take regular Tums. The recommendation to have your B12 and MMA levels checked is still valid since a vagotomy and possibly a pyloroplasty were routinely done together in the referenced time frame. Both can cause a suppression of the intrinsic factor which is necessary for the absorption of B12.If you did have a pyloroplasty which opens the outlet of the stomach, you could be suffering from dumping syndrome. If you experience the symptoms immediately after eating that is probably the cause. Your stomach is not broken, merely mistreated. When you train your stomach to accept only a bland diet with no fiber or bulk, it responds with the syptoms you descibe. The vagus nerves, by the way, also control heart rate and rhythm. If you do decide to self medicate with B12, get a sub lingual lozenge of at least 5000mcg.You will notice an almost immediate change
Suggest a vitamin B12 and MMA test from you doctor. Stomach surgery including a vagotomy decreases acid secretion and the intrinsic factor which aids in absorption of vitamins.If your doctor knows your medical history and has not recommended or done a vitamin B12/MMA test, maybe you should think about finding another doctor. You have classic deficiency symptoms.