a collapsible bag for use in containing and dispensing a liquid , such as in a bag - in - box arrangement , and a method for making the bag , wherein an elongated reinforcing strip is attached to the outside surface of one of the bag walls and extends from adjacent to the spout to remote therefrom , and a plurality of grooves are provided in the strip and also in the portion of the bag wall attached to the reinforcing strip , thus providing liquid passageways inside of the bag to achieve complete withdrawal of the liquid from the bag as the bag collapses , without the expense and complication of having to insert a separate dipstrip member into the bag and to connect it to the spout .