Well when you go to every specialist and try every type of milk and every diet change imaginable it gets there through a diagnosis of exclusion.

Trust me, the debugging is a big part of the trouble. Everyone is telling you to debug, but that is actually the thing you have to learn to stop doing. Your brain is telling you to debug. But it can't be debugged. I watched multiple women have mental breakdowns trying to debug a baby with a 6 month streak of colic. Eventually their brain just goes psychotic because a baby screaming 6+ months non-stop with nothing wrong while people frantically try to solve the problem is basically sever mental torture. It is not the hours, or days, or even weeks of screaming that get to you, it is the months of never ending ear-pearcing torture that nothing will fix, and they will not fucking sleep because they just want to scream for all of their sleep as well and naturally the caregivers won't be sleeping either due to this. And you cannot rely on crying to figure out when to feed, when to change a diaper, when the baby needs sleep, or some gentle motion -- all of your indicators are worthless.

It is a hell for the baby and it is a hell for the parent. People struggling with this generally do not have any more children. Any other stage past baby for such child is 99% easier, I laugh when people say babies are the easiest stage.