Welcome to HCM
Your wife is sufferibg from Diabetes
Type II uncontrolled , as you say now it is normal blood sugar level
But her watery loose motion
problem may be unrelated to diabetes so it is possible she has Gastroenteritis
which should be treated with correction of dehydration
and investigate the cause after cosulting your treating Physician get Stool R&M,Creatinine
level and Electrolytes.
Take care or potable water,also check with your Physician if you are taking drugs any one which can cause loose motion.
If infection is there easily trated with prescription medicines, but if her diabetes is longstanding and if possibly she has autonomic neuropathy it may be trouble some ??
Just take care of her blood sugar level .
I hope nothing serious is there and she should improve in few days.