  We derive an evolution equation describing the high energy behavior of the
cross section for the single diffractive dissociation in deep inelastic
scattering on a hadron or a nucleus. The evolution equation resums multiple
BFKL pomeron exchanges contributing to the cross section of the events with
large rapidity gaps. Analyzing the properties of an approximate solution of the
proposed equation we point out that at very high energies there is a
possibility that for a fixed center of mass energy the cross section will reach
a local maximum at a certain intermediate size of the rapidity gap, or,
equivalently, at some non-zero value of the invariant mass of the produced
particles.
