Below is an instruction from Human. Write a response.
    ### Instruction:
    What to do for What I need to know about Gas ?
    ### Response:
    - Gas is air in the digestive tract.  - Everyone has gas. Burping and passing gas are normal.  - Gas in the digestive tract is usually caused by swallowing air and the breakdown of certain foods in the large intestine.  - Most foods that contain carbohydrates can cause gas.
    