The present disclosure relates to devices and methods for delivery of a ferrofluid to a targeted treatment site, such as delivery of a ferroadhesive to a pathological fistula to occlude the fistula. A device includes a catheter having a lumen and a distal opening. A hollow solenoid is coupled to a distal section of the catheter, and a hollow core of the solenoid allows passage of a ferrofluid through the catheter and through the hollow core so that it may exit past the distal end of the hollow solenoid. The solenoid may be selectively actuated to maintain or control the position of the delivered ferrofluid.