The present invention provides a cannula guide tube; and a kit with the cannula guide tube, a flexible transparent cannula or a transparent catheter with an inflatable balloon at the catheter end, and an exploratory device. The kit is for irrigation, suction and washing out purulent or liquid discharges from bacteria infected sinuses. First, the exploratory device is used to find the entrance orifice to a sinus; second, the cannula guide tube is positioned in the sinus orifice entrance; and third, the flexible transparent cannula or the transparent catheter is inserted through the cannula guide tube into the sinus. The flexible transparent cannula or transparent catheter is used to suction the purulent or liquid discharge and to irrigate and wash out the sinus. The cannula guide tube has an opening before the tube end, wherein the opening allows seeing the flexible transparent cannula or transparent catheter inside the tube and the flow of purulent or liquid discharge suctioned from the sinus, as the purulent discharge flows throughout the flexible transparent cannula or the transparent catheter.