Bradypepsia is the medical term meaning slow digestion.
A Medical term for slow and unnoticed is insidious.
Diastasis
Tetany is the medical term meaning inability to relax the muscles.
Costochondritis is inflammation of the muscles in the ribs
Colic is the medical term meaning spasm of the visceral muscles.
intercostal muscles - from inter meaning 'between', and costa meaning 'rib'
rigormortis
Myologist is the term meaning specialist in the study of muscles, but an orthopedist is the typical specialist physician who treats muscle problems.
Tetany is the medical term continuous spasm of muscles; tetany may result from hypocalcemia.
Contracture or contraction
Bradykinesia is the medical term meaning slow movement. Bradykinesia may be seen in Parkinson's disease or depression.