@matigo Feeling cold during the change sometimes does it, as they end up bare-bottomed for a bit.
Sensitivity to whatever's in wipes or creams could also make the change uncomfortable.
Lying down flat can also make reflux a bit uncomfortable; putting a baby pillow or folded up clothing on the changing table and setting their head on that can help.
They also sometimes don't like how you're gripping them to position for wiping and diapering.
One of the great frustrations of the pre-verbal stage is that it's all a big guessing game as to what's actually bothering them. You just know something is (and how severely based on the volume).
// @hazardwarning