School distress or alienation (schoolwork dislike), difficulties in school performance as well as boredom of especially gifted pupils can cause psychosomatic symptoms like:
Stomach and gastrointestinal functional problems
Irritability and conduct problems
Feeling low and tired
An increase of psychosomatic symptoms is often associated with low self esteem or low self efficacy (ability to cope with difficult situations, problems to socialize and making friends or asking for support and cooperation).
If your child experiences some of these symptoms more than once a month you should ask for any problems at school.