Duh...(or "Derr..." depending on your accent)

Finally figured out that the key to managing magnesium-induced reflux is to not take it right before bed. I was just doing that because that's when I usually take calcium, and they seem to go together nutritionally speaking. But in terms of physics, if you're going to open a drawstring bag and hope to keep the contents more or less inside it, doesn't it make sense to open in when it's in an upright position, rather than lying on its side?