My boy had two separate problems at different stages. The first was trapped wind. I think I read somewhere that a babies intestines are not fully developed at birth and so trapped wind causes them real pain.

The second problem was a recurring middle ear infection that would always start at bedtime. This is because more pressure can build up in the inner ear as soon as the baby lays down or becomes inactive.

Both cases cause the child serious pain and simply leaving them to cry it out is not going to help and will potentially cause more distress to the child. I also agree that, with some kids, it is more of a routine. But usually three or four minutes is all it takes for that kind to give in.

All the best.