Hi welcome to Health care magic forum.
You had pain in the center of the stomach, and loose motions, the cause of the pain is infection of the intestines, called gastroenteritis
I advise you to consult a physician for diagnosis and treatment. You may need to have infusion of I.V.fluids, for recovery from the dehydration
due to motions. The pain may also be due to dehydration of the intestines as well.
Besides you may need to have anti spasmodics as well for relief of pain.
Wishing for a quick and complete recovery.