Babies spit up. It doesn't matter how long since a feeding, people just say an hour so the stomach has more time to settle. If your baby has acid reflux you would most likely see him arching his back, screaming in pain, etc. My daughter had it and it was very obvious that it wasn't the normal spit up. My daughter is 17mo, has never slept through the night. At 6mo she had about 10 hours of sleep at night. Most days I was lucky to get a 1 hour nap out of her.
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