Escherichia coli is one of the most studied bacterial model systems in modern biology. Under normal laboratory conditions, E. coli adopts its characteristic rod shape. However, during stress conditions, E. coli has been shown to undergo conditional morphology changes to inhibit division and grow into highly elongated forms. In this study, we used an in-vitro infection model system combined with advanced imaging to show uropathogenic E. coli rods dividing to form and proliferate as cocci inside human bladder epithelial cells. In these intracellular bacterial communities, the frequency of cell division outpaced the rate of cell growth, resulting in smaller cocci cells. This mechanism was guided by an active FtsZ-governed division machinery, directed to mid-cell by division-site placement systems. The findings of this study show how a previously uncharacterized level of morphological plasticity occurs in bacteria with traditionally well-defined rod shape.