my wife have to much pain in periouds time what i...

What is the treatment of Menstrual Pain ?
It's common in almost all ladies to have menstraual symptoms before and during menses such as abdominal cramps that can be relieved by applying warm packs on the abdomen and drink herbs with enough time to rest during the day with balanced healthy diet and you can use medication such as Spasmin tab twice daily , if the pain is associated with irregular period you'll be prescribed to take OCPs by doctor 
What are the investigations ?
No need for investigations unless there was another problem such as irregular menses or heavy menses you will have to do hormonal tests such as LH FSH 
 
What are the symptoms of periods ?
Adominal pain 
headache 
Lower limp pain 
nausea 
mood swings 
breast pain
Advice :
follow the previusly mentioned instructions