Malaise is a general term for bodily discomfort.
Bradypepsia is the medical term meaning slow digestion.
Chyme is the medical term meaning stomach contents during digestion.
Acid Reflux is the medical term for regurgitation of stomach acids.
Dyspepsia
apepsia
barotrauma
There is not a medical term for incomplete digestion. Something close would be Dyspepsia. Which basically is a catch all phrase for anything pertaining to difficulty digesting. Example: acid reflux, bloating, discomfort etc.
Dysphagia is the medical term for difficulty swallowing.
catabolism
Phagocytosis is the medical term meaning digestion and ingestion of microorganisms by white blood cells.
Eupepsia is the medical term meaning good or normal digestion. In contrast, dyspepsia means difficult digestion.
The medical term for gullet is esophagus. The esophagus is the tube that connects the throat to the stomach and is responsible for transporting food and liquids to the stomach for digestion.