I see lots of discussion on the topic of having to cough up mucus after meals. Often the explanation is GERD or Post-Nasal Drip. Yet many people comment that taking strong acid reducers like proton pump inhibitors (Nexium, Protonix, omeprazole, etc.) or anti-histamines does not help.
What people do not realize about GERD and proton pump inhibitors is that the drugs do not stop GERD, they merely decrease the amount of stomach acid produced (which can have other not-so-good effects over the long term, particularly in the elderly). If, as frequently happens with GERD, it is caused by a weak lower esophageal sphincter, then you are going to get some reflux particularly at night lying down.. Sometimes trying to spend most of the night sleeping on your left side (because that puts the esophageal opening to the stomach higher) might help.
So, even though you may not feel any symptoms of acid indigestion that does not mean you are not having reflux problems. Short of stomach surgery (fundoplication) to tighten the sphincter, there does not seem to be much that can be down about this as far as I can tell. Even the operation usually has to be repeated in 4-5 years, and just having it can create more swallowing difficulties.
This discussion is related to Excessive coughing/mucus after eating