Abstract <p>Inclusive processes at high energies are studied in a non-perturbative approach in QCD using a modified quark-gluon string model. Theoretical and experimental aspects of diffraction dissociation are discussed. In the calculations of cross sections, the parameters of complex nonlinear trajectories of Pomeranchuk and Reggeons are used. Particular attention is paid to elastic and inelastic processes at LHC energies.</p>