Boiled Rice Soup or Congee - Another natural Thai cure for a stomach ache is boiled rice soup, also known in Thailand as 'congee' or 'yoke'. Originally from China, Thais like to eat it in the morning, particularly as a cure for an upset stomach as a result of drinking too much alcohol as it settles the stomach. It's a wonderful plain food to keep down if you're also vomiting, and it stops diarrhea.