The cleanup and the drying are two phases. Getting the sewage and contaminated materials out is fast; drying the structure to a safe, verified moisture level is what takes the days. Rushing or skipping the drying is what leads to lingering odor and mold weeks later.
How long depends on the category and reach of the water, the materials affected, and airflow. A hard-surface floor caught quickly dries fast; a finished basement with saturated drywall, carpet, and subfloor takes longer and involves more removal.