Answer: -The trap is probably filled with solids, sediment or whatever. You may be able to clear it with a plunger. Flood it and then plunge the hell out of it with a good plunger. Don't be afraid to splash the water in doing so. -Rodding the line may clear out the problem. But the drain is probably full of sand and silt. I've found that a jetter does a much better job on sand and silt than rodding. If the drain isn't clogged too bad, you can probably use a blow bag to clear the pipe.