need answers

My mum has this pain on left side. She 's had all sorts of tests and xrays
But they came up negative. The only thing that showed was the inflamation (inflammation)
In her stomach but the doctors couldnt tell us exactly  why.
However there is one doctors that thinks its a tumor that hides inside the stomach cells
So therefore it will never show in xrays/scans or any other test. Meanwhile the pain is getting worse and there is nnothing we can do to make it go away.
The only pain relief shes on is morphine. But thats causings hessther problems as well. Such as memory loss,
Dizziness, sleepless , headache and weight loss.
Please give me a solution. Tell me what to do. How do i help her

[Dr Santos]

Hi,
How is your mom?  What other symptoms are present? Inflammation of the stomach lining or gastritis may be acute or chronic and the most common causes of gastritis are H. pylori infections and prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs).  To determine the underlying cause and to rule out tumor or malignancy, further evaluation may need to be done such as blood and stool test, H. pylori test and even biopsy. A referral to a gastroenterologist may also help. Take care and do keep us posted.