When our son was a baby, he spent many an hour crying and screaming. It seemed like almost anything would set him off – eating too much, laying down flat or starting a new formula or medication. My husband and I couldn’t help but worry what our son’s disposition would be like as a toddler and beyond. Would he spend the rest of his days and nights screaming and crying?

Four years later, we see we didn’t need to worry about that aspect of his illness. Our son still has reflux and a very...