hi,
thank you for your query,
the symptoms you are describing seem to point towards pain in a "retractile testis".a retractile testis is one which retraces the path of the testicular descent and lies in groin or the abdomen
Common causes of
testicle pain include:
Injury
Infection or inflammation
Testicular torsion as testicular torsion has been ruled out.the possible causes of pain due to infection include-
Orchitis -- inflammation of one or both testicles, which may be caused by bacteria or a virus like mumps. Orchitis can occur at the same time as epididymitis
Another important cause can be an underlying hernia which has manifested after the surgery.
Also there are chances that there is
cremaster muscle spasm causes these contractions.
i would suggest-
Ultrasound of the testicles
Urinalysis and urine cultures
MMR vaccine for the kid
in any case i would suggest you get a check up by an
urologist and a surgeon to pinpoint the cause.
thank you for your query,
wishing you good health