For many reasons, a "go-around" once on the runway in a large airplane isn't necessarily a good idea. A large airplane, indeed most any turbojet airplane, isn't operated with "touch and go" landings like a light airplane might be. Many turbine airplanes can be made to go around with the boards extended. However, go arounds are really the same as missed approaches, and for the most part, boards aren't out the same time as flaps until the aircraft is on the ground. Ensuring the boards are retracted as part of any balked landing or go-around proceedure is necessary, however, automatic status not withstanding.
If the aircraft has slowed to the point of being on the runway, into reverse and spoilers auto deployed (such as bringing #1 or #4 engines into reverse, for example), attempting to reverse the configuration and go would require a pretty darn good reason. If autobrakes are used, they're probably already operating at this point. Engines would have to be brought out of reverse thrust, spooled back up evenly, the aircraft reconfigured on the roll for takeoff, braking disengaged, and the aircraft accelerated to a rotation speed again, with a good percentage of the runway already behind.
If an exigent circumstance such as a pending runway incursion occurs downfield (another aircraft taxiing or under tow entering the runway for example), one may do nothing more than increase the impact energy if one is already on the ground and slowing, when one attempts to go. A max effort stop with decreaing energy may be the best option at that point.