Laura has a voiceover at the end of the Season 9 episode entitled "Home Again" in which she says that Albert comes back to Walnut Grove as a doctor later on. However, this is a highly debated issue because in the movie "Look Back to Yesterday", Albert contracts a rare blood disease and it is inferred that he died, although that is also debated. So he could not come back and be a doctor if he died at the end of LBtY.
Also, in the movie "The Last Farewell", the residents of Walnut Grove blew up the town. Therefore, unless they rebuilt the town, Albert couldn't come back to Walnut Grove to be a doctor, because nothing was there mostly except ruins.
In the second part of the two part show "Home Again", Albert and Charles are in Mr. Edwards cabin as Albert is going through withdrawal. In one scene, he gets the shakes and then throws up all over himself. In the next scene, the shakes start again and his pants are completely clean.