We report computations of the short- and long-distance (scaling) contributions to the square-lattice Ising susceptibility. Both computations rely on summation of correlation functions, obtained using nonlinear partial difference equations. In terms of a temperature variable τ, linear in T/Tc-1, the short-distance terms have the form τp\(ln\|τ\|\)q with p>=q2. A high- and low-temperature series of N = 323 terms, generated using an algorithm of complexity O\(N6\), are analyzed to obtain the scaling part, which when divided by the leading \|τ\|-7/4 singularity contains only integer powers of τ. Contributions of distinct irrelevant variables are identified and quantified at leading orders \|τ\|9/4 and \|τ\|17/4.