We present a smooth muscle model which enables the simulation of its contraction under functional electrical stimulation (FES). The model takes into account chemical and microscopic mechanics of the contraction. In order to illustrate the model performances, we simulate a well known example: the behaviour of the bladder under electrical stimulation using a Finetech / Brindley implant. This approach allows to compare our qualitative results with experimental data available in the literature. Simulated output (pressure, volume and urine ux) show good consistency both in shape and time course. With the objective to obtain quantitative simulations, we propose a setup for animal in-vivo experiments which should allow us to perform the identication of the model parameters. Preliminary experimental data is presented.