Unblocking an underground drain pipe can be challenging and often requires professional assistance. Attempting DIY solutions may worsen the problem. Professionals typically use specialized tools like drain snakes or hydro-jetting equipment to clear blockages. In some cases, a video inspection is performed to identify the exact location and nature of the blockage. Preventive measures include avoiding excessive grease or debris disposal. If you suspect a blockage, it's advisable to consult with a licensed plumber for an accurate assessment and effective resolution.