A cable

A cable is a long piece of faeces which is partially ejected from the anus. Generally, the rule is that a cable must be of such length that is is touching the water whilst still coming out of the anus. (This is prevalent in toilets which only fill the lower faecal cavity with water, not half fill like in the Unites States). After defecation, the toilet may require several flushes to allow for the process of hydraulic action to break down your massive monolith and remove it from the bowl.