Add swipe left/right to web page, but use default swipe up/down

Remove event.preventDefault(); from all functions. In the function processingRoutine() {} add event.preventDefault(); for what you want.

function processingRoutine() {
    var swipedElement = document.getElementById(triggerElementID);
    if ( swipeDirection == 'left' ) {
        // REPLACE WITH YOUR ROUTINES
        //swipedElement.style.backgroundColor = 'orange';
        event.preventDefault();
    } else if ( swipeDirection == 'right' ) {
        // REPLACE WITH YOUR ROUTINES
        //swipedElement.style.backgroundColor = 'green';
        event.preventDefault();
    } else if ( swipeDirection == 'up' ) {
        // REPLACE WITH YOUR ROUTINES
        //swipedElement.style.backgroundColor = 'maroon';
    } else if ( swipeDirection == 'down' ) {
        // REPLACE WITH YOUR ROUTINES
        //swipedElement.style.backgroundColor = 'purple';
    }
}