If you have an old fashioned mop, just push it down the loo and thrust it up and down a few times, if not, get a large towel wrap it around your fist and use that to thrust. good luck.
Old wire coat hanger, undo it so its one long wire if you see what I mean and have a good poke around. I've had to do this in the past when like yours my little one has gone nuts with the paper.
go and look outside for the main drain that the lavatory pipes drain into - lift that and clear any blockages. I've just done mine recently following this advice (from jack- the -hat if I remember correctly) and all is fine now. It took lots of buckets of water and much prodding but everything is flowing clearly now. I check it at regular intervals too.
I use my method daily when we have residents that put giant incontinence pads down the loo, they do go around the bend before they get lodged, it works every time.
Lol boo that was the method i had to use at our friends last week to clear there blockage, friend had no plunger and no clue how to deal with it. the only thing was i put the length of coat hanger outside as our friend didnt want it inside. Only the boys used it without realising on the cars engine.....