This paper presents a detailed analysis regarding the generation of a dispersive wave (DW) and four-wave mixing in the noninstantaneous, nonlinear response of solvents using a commercial photonic crystal fiber filled with carbon disulfide (CS2) where the beam is pumped in the anomalous dispersion domain. The main finding is the fact that the output spectrum changes from coherent DW to incoherent modulation instabilities just by changing from constant to variable nonlinear parameters. This study can be extended to other solvents including ethanol, methanol, and butanol.