Welcome to the forum. Your girlfriend needs clinical assessment for the symptoms from which she is suffering. She should undergo investigations ( blood tests and ultrasonography
). Such an acute pain can be due to gastric ulcer. Her general heath is not fine. Tto diagnose the cause of twitchings, body jolts, etc she may need to undergo a CT or EEG. It will be better to let her have a thorough general examination.
To relief gastric pain she can take antacids, muscle relaxants. She should keep herself well hydrated and take meals in time.
Take her to the emergency room before symptoms worsen. Take care.