Vagotomy and Pyloroplasty Operation

Hi. I had this operation 45 years ago at the age of 21. My digestive system has never been what you might call normal. I suffer from IBS mixed but predominantly D and Dumping syndrome. I've tried improving my condition with diet and pills and had more cameras down my throat and bottom than a model on a photo shoot. I've given up on the NHS; the only advice they keep giving is to eat more fibre. Yes, I have tried that, but it just makes matters worse. I'd love to get feedback and hopefully good advice from anyone who has had the same operation.