Hi Mags936,
A purchase order will need to be saved and copied to a bill to remove the item from the low stock list, but you do not have to send it to the supplier if you would prefer not to. When creating the purchase order and saving it, look for a dropdown arrow next to the 'Save and Send' button. Select this and you will have options to Save, or Save and Close - either will save without emailing the supplier. Once you've done this, you can copy it to a bill and Save this as well without sending it.
Please let me know if you have further questions as I'm here to help.
-Kass