Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Gas ?
    ### Response:
    Everyone has gas. Most people pass gas 13 to 21 times a day. Passing gas through the mouth is called belching or burping. Passing gas through the anus is called flatulence. Most of the time gas does not have an odor. The odor comes from bacteria in the large intestine that release small amounts of gases that contain sulfur.
    