DIS data and the problem of saturation in small-x physics

New experimental data from HERA explore the region of very small x and small and moderate $Q^2$. We study the role of unitarity corrections in the description of these data. For that, we propose a model separating the small and large components of the $q\bar q$ fluctuation. This model gives a unified description of total and diffractive production in $\gamma^*p$ interactions. In this model unitarity corrections are controlled by diffraction data.