A blocked line causes gurgling toilets. The negative air pressure caused by the clog is pushing back, causing the sound. This is caused by a drain or toilet clog, blocked vent stack, or mainline or sewer line problem. Using a plunger, try to dislodge the clog. If this doesn’t work, you’ll want to try a snake or auger. If this doesn’t solve your problem, call Howell Services. Our licensed professionals have the expertise and heavy-duty equipment to clear your clog in no time.