We report on the theoretical statistical characterization of a single-photon source based on the stimulated four-wave mixing process inside an optical fiber. We quantify the photon statistics by means of the expectation number of photons generated on the signal and idler waves, $\langle \hat{N}_s \rangle$ and $\langle \hat{N}_i \rangle$ respectively, and Mandel's $Q_s$ and $Q_i$ parameters. The obtained solutions take into account the spontaneous and stimulated Raman contributions for the generation of the idler wave. Results show that the idler wave generated inside the fiber follows a super-Poissonian statistics. Findings also show that the signal wave change their own statistics from a Poissonian to a super-Poissonian, due to the interaction with the pump field and the optical fiber.