Whatever you drink, you can use in an enema. Municipal water supplies are far more regulated than bottled waters, and some bottled waters are literally nothing more than tap water someone puts into a bottle.
As far as filtered water is concerned, "filtered water" can be nothing more than water passed through a 30 micron particle filter. They are cheap and only take out solids. This is what most colon therapists have that I have been to. Some might use a carbon filter, but those get more expensive and they need to be replaced more often. I have seen the filters they use when I go for colonics, usually 3-4 per year for over 15 years now because I like being pampered and able to relax. Beyond that, you can have 5 micron, then carbon filters which filter out smaller particulate matter and the carbon will take out a degree of heavy metals. The best filtration is reverse osmosis. Our house has a "whole house" 5 micron filter (about the size of a 45 gallon garbage can) that filters everything except water used in the pool and watering the lawn. It has a timer where we set it to automatically backwash itself every night from 3 am to 4 am. In the kitchen, we use reverse osmosis water for cooking and drinking because I like the way it tastes. It tastes like totally tasteless water, which is great because I am a coffee, espresso, and tea fanatic. A reverse osmosis filter for the "whole house" isn't very practical because they don't have the capacity to run appliances or showers and even the ones in our kitchen only store about ten gallons in its reservoir, so after you fill a couple of 24 quart stock pots (I do massive cooking for company) you have to let the system re-fill itself which can take a few hours.
So, what I use is the water from the bathroom, which is simply run through the house particle filter, which does not take out anything dissolved, like heavy metals--but we have a very clean water supply where we live. Besides, I occasionally use the closed system type colonic device my husband constructed that uses continuously running water and a speculum that stays in, just like at a colonic spa. Like going for a colonic, it is very relaxing, and I love the water flowing in and out, but unless I have my husband there and controlling the inflow and outflow of the water, the colonics at the spa are more relaxing because all I have to do is lay there! If I were to use the reverse osmosis water from the kitchen, I would have to heat it in the microwave or on the stove, which isn't very convenient.