Duplicates...don't necessarily get more answers! As noted, a properly done one can look no different than a bathroom done anywhere else in the house, although it requires breaking up the concrete to run the drain lines to a new sump that contains the ejector pump. People do this all of the time. The only potential problem with this is where they have used tensioning cables in the slab...you can't (or shouldn't) cut one of those while excavating things or you risk injury and or slab failure. They use this type of construction in CA or where earthquakes are more common (from what I hear). In the rest of the country, I'm not sure how common they are (or even in CA for that matter). In this construction, there are cables run through the slab, and after the pour has cured, they tighten them up so the whole slab is under tension, helping to prevent cracks during a shaker.
The only time you need to pump the sewage is if your run to the sewer is higher than it is possible to allow gravity to do the task.
