Why toilets block
Blocked toilets can be a real nightmare for many reasons. Severe blockages can cause flooding, bad smells, and you'll be unable to use the toilet until the blockage is cleared. Blocked toilets are mainly caused by flushing items down the toilet that shouldn't go down.
Never flush: wipes (even ones labelled 'flushable'), nappies, sanitary products, plastic, cotton wool, paper towels, dental floss or anything that isn't toilet paper. Toilet paper is designed to disintegrate; almost nothing else is.