I've mentioned that lactose is often used in brewing beer to make the variation called milk stout. Wikipedia gives this definition:
Milk stout (also called sweet stout or cream stout) is a stout containing lactose, a sugar derived from milk. Because lactose is unfermentable by beer yeast, it adds sweetness, body, and calories to the finished beer. Milk stout was claimed to be nutritious, and was given to nursing mothers, along with other stouts, such as Guinness. The classic surviving example of milk stout is Mackeson Stout, for which the original brewers claimed that "each pint contains the energising carbohydrates of 10 ounces of pure dairy milk".
Which should get you to say, "Wow, that's a lot of milk."
How bad is milk stout for you? As I wrote in Lactose in Beer?
How much lactose is left in the beer? You won't be surprised to learn that it varies too much with the recipe for a definitive answer. I did a calculation from one recipe and found that it resulted in about half as much lactose as a glass of milk. Other sources say, however, that the lactose content is small for some milk stouts. If you drink for flavor and not a buzz the lactose shouldn't be a problem.
That Wikipedia page also mentions a variation called "coffee stout."
Dark roasted malts, such as black patent malt (the darkest roast), can lend a bitter coffee flavour to dark beer. Some brewers like to emphasize the coffee flavour and add ground coffee. Brewers will often give these beers names such as "Guatemalan Coffee Stout", "Espresso Stout", "Breakfast Coffee Stout", etc.
The ABV of these coffee flavoured stouts will vary from under 4% to over 8%. Most examples will be dry and bitter, though others add milk sugar to create a sweet stout which may then be given a name such as "Coffee & Cream Stout" or just "Coffee Cream Stout". Other flavours such as mint or chocolate may also be added in various combinations.
I noticed a mention of one at the phillyburbs.com site.
On tap now at Triumph Brewing Company of New Hope is the Coffee and Cream Stout. A hybrid style of beer created by crossing coffee stout with milk stout. Adding unfermentable milk sugar (lactose) in the kettle results in a texture that is rich, chewy and, quite literally, creamy.
One more thing you have to watch out for, making you even more paranoid. You can thank me later.