The following side effects are listed as 'common' or 'very common' by the British National Formulary (which is the standard reference work used by doctors and pharmacists):
Asthenia [ = muscle weakness and/or lack of energy] ;
Diarrhoea ;
Gastrointestinal discomfort ;
Gastrointestinal disorders.
To view less common side effects, see here:
https://bnf.nice.org.uk/drug/ezetimibe.html#sideEffects