In older age, but nowadays also in often in younger people with certain medical conditions there may be problems of digestion which can manifest themselves in gas, bloating, heaviness extreme tiredness after meals, nausea, fogginess and more.
Often this is the result of overeating, wrong combinations of food [by many doctors this is not accepted] or a lack of stomach acid and digestive enzymes.
Of course, the easy to correct conditions should first be discussed and addressed, if possible.
Alas, the medical profession has often been corrupted by easy and profitable solutions and this has shown itself by prescribing routinely PPI”s [Proton-pump inhibitors]like Omepradex[Losec] and others, wonderful drugs for emergencies and for some very rare diseases but a disaster for regular use for extended time [ lookup PPI in my WordPress for more articles ]
All older doctors knew that the so-called “bitters” could be most useful for the above mentions gastrointestinal conditions. These were given in as herbs in all kinds of forms.
I found on IHerb a very good formula, which can be used for anyone with these problems at least for a short time. .https://il.iherb.com/pr/garden-of-life-mykind-organics-liver-bitters-detox-spray-2-fl-oz-58-ml/85583
One of the oldest bitters on the market is Angostura, which you may know.
Article about “bitters:: https://www.acouplecooks.com/what-are-bitters/