This paper proposes a new operation management scheme (OMS) for next-day complex power scheduling in an islanded reconfigurable microgrid. Energy supply in the microgrid comes from wind turbines and photovoltaic generators as renewable dispersed generators (RDG). Meanwhile, there are two microturbine units and a fuel cell unit as dispatchable distributed generators (DDG). Also, a battery bank energy storage system (BESS) is integrated. The microgrid has a number of controllable tie-switches to change the microgrid configuration and supplies residential, commercial, and industrial loads with different electrical models. Some of loads participate in a demand control program. The OMS is mathematically formulated as a multi-period mixed-integer stochastic nonlinear optimization. It has to decide the hourly power share of each DDG, the states of the control switches, and specifications of demand response. The OMS aims to minimize the total operation cost, unmet load, and curtailed renewable power maintaining all technical constraints. The uncertainty of renewable resources and load is analyzed in the OMS by Monte-Carlo simulation while scenario-reduction approach is used to reduce the computational burden. Besides, a new version of bat algorithm (IBA) is developed as a robust optimization solver. Simulation results and comparative evaluation of the OMS are presented using a 45-bus case study system to prove the merits of the method.