Hi there, Sorry to hear that you re still having difficulty. Lansoprozole is a good medication for ulcers, and people usually don t develop tolerance to it. Sometimes, some people still produce increased acid for other reasons, or sometimes still have symptoms of GERD (gastroesophageal reflux disease) despite medical treatment. It sounds like you ve done all the right things here and you re still having difficulty. I often see patients like you sent by their GP s who are looking for answers. - A common cause of your continued symptoms can be due to hiatal hernia - this is a defect that causes the esophageal sphincter to be in an abnormal position, which causes acid to spill back into the esophagus. I d recommend a test called an upper GI. This is a test where you drink some contrast and it can tell if your spinster has herniated (in the wrong place) which would explain your symptoms. Surgical repair is usually effective in resolving your symptoms - Another cause could be due to ulcers. If you ve never had a endoscopy (camera) to look for ulcers, I d recommend that. - Another cause, although much rarer is a tumor called a gastrinoma, which causes the stomach to cause increased acid production, despite use of acid reducing medications. A blood test testing for secritin is a good place to start. It sounds like your GP has done all the right things, but I d strongly recommend he refer you to a Gastroenterologist who has experience in treating GERD. I d also recommend not taking any NSAIDs such as ibuprofen, not smoking, and continuing your medications in the meantime. Smoking and NSAID s can definitely worsen your disease. I hope this is helpful. Please feel free to contact me if you have any further questions.