  We consider near-critical two-dimensional statistical systems with boundary
conditions inducing phase separation on the strip. By exploiting low-energy
properties of two-dimensional field theories, we compute arbitrary $n$-point
correlation of the order parameter field. Finite-size corrections and mixed
correlations involving the stress tensor trace are also discussed. As an
explicit illustration of the technique, we provide a closed-form expression for
a three-point correlation function and illustrate the explicit form of the
long-ranged interfacial fluctuations as well as their confinement within the
interfacial region.
