We went to the GP yesterday and he did a physical exam again. He said he's sure there's gas / air trapped in there and it's what's causing the bloating / pain. He prescribed some medicine and we'll see how that goes and that he can't advise him to get an ultrasound right now as from a clinical perspective, there are no other symptoms to worry about. I feel slightly more at ease given his confidence but still somewhat worried as I've seen plenty of people misdiagnosed who were given the same medication when in reality there was something much more wrong going on. And yes, we're using the German Health system.