In this paper we present a new experimental setup combining laboratory high resolution computed micro-tomography (MCT) with a flow microcell specially designed to reproduce in-situ multiphase flow experiments and monitor the fluid distribution at the pore scale. The objective is to describe the fluid saturations and distribution at different steps of the capillary pressure cycle (drainage and imbibition) while maintaining the sample under pressure in the cell to avoid fluid re-distribution. Experiments have been performed on a monomodal sandstone where the total porosity is resolved by the MCT. We compared successfully the saturation profiles calculated from the mean grey level of the 2D cross sections and the saturation profiles calculated by 3-phase image segmentation. The two above mentioned methods can be combined in bimodal pore systems to evaluate the fluid saturations in both micro (unresolved) and macro (resolved) porosity. Finally, we describe the distribution of each fluid at the different steps of the drainage-imbibition cycle and the influence of the pore geometry and interfacial tension on the oil trapping.