We propose to investigate the different types of short-range order (magnetic, structural and charge) present in La2-xSrxCoO4 with x = 0.20 and 0.25. Longitudinal polarized neutron diffraction will be used to separate the magnetic and non-magnetic diffuse scattering. Previous measurements performed on IN20 on a sample with x = 0.33 revealed a complex ground state in which incommensurate charge and magnetic stripe order coexists with commensurate checkerboard charge order. We aim to discover how the proportion of the incommensurate and commensurate ordered phases varies with doping. The results will clarify why the magnetic excitation spectrum has a characteristic hourglass shape similar to that observed in many copper oxide high temperature superconductors.