An anti-clogging catheter includes a tubular cannula defining a fluid passageway and shaped and tipped to removably insert within and be removed from a human body, where the cannula has a proximal end with a first interior surface defining a first interior diameter and a distal end with a second interior surface defining a second interior diameter that is smaller than the first interior diameter. A stylet is movable within the fluid passageway between the proximal end and the distal end and has an outer diameter substantially equal to the second interior diameter.
