Toilet drain problem

Nov 19, 2018
Real Name
Douglas B. Galarza
On the side of my toilet, there is an inlet to access the sewage pipe if blocked. Lately, when I flush the toilet the water rises up to the ream in the bowl and slowly goes down like if there is a blockage. I purchased a handheld eel from Bunnings and inserted the 7,5m long eel in the inlet on the side of the bowl.

When I flushed the toilet with the outlet open to the air, the water evacuates normally but if I seal the outlet the water raises up again to the ream and slowly goes down. Also when the outlet is open there is a big gasp of air coming out of this outlet while the water flashes down and then after few seconds a kind of blob-like an air bubble coming up to the surface.
I had done drain cleaning of the mainline last month itself.

Do I have a blockage along the sewage pipe? And if so, why does it flush without problem when the side outlet is open to air?

Any help would be appreciated.