The main point was that failure to digest something doesn't mean that you are allergic or intolerant. My impression was that this was what the example with babi

The main point was that failure to digest something doesn't mean that you are allergic or intolerant. My impression was that this was what the example with babies' bodies "rejecting" some foods that they cannot process implied. Humans can eat stuff they cannot digest (fiber, corn kernels without chewing, anyone?) without adverse effects, stuff will just pass through. Unless you're eating nails or glass, but that's a mechanical damage...