Indigestion from cola consumed during days off (9)
I believe the answer is:
dyspepsia
'indigestion' is the definition.
(synonyms)
'cola consumed during days off' is the wordplay.
'cola' becomes 'Pepsi' (cola brand).
'consumed during' indicates putting letters inside.
'off' indicates anagramming the letters.
'days' with letters rearranged gives 'dysa'.
'pepsi' going into 'dysa' is 'DYSPEPSIA'.
'from' is the link.
(Other definitions for dyspepsia that I've seen before include "It was enough to make any man sick" , "internal upset" , "Stomach problem" , "it could result from rushing courses" , "stomach complaint" .)