Stomach disorder

I have the most wonderful adult  son kind generous and beautiful.  He was diagnosed with Aspergers as a child   Alll his life he has suffered server stomach pains as a baby it was colic as a child it was anxiety now it’s IBS  he has no life we, e had test after test and yet still he goes through this almost daily my GP now tells him it’s his brain telling his gut  he can’t go out because he never knows when he’s going to get a flare up I think we have tried every pill and potion the NHS has to offer  I can’t watch him suffer like this having constant pain and no life  I’m thinking of trying to get him a private capsule endoscopy. I’m just wondering if any one suffers this way too