What disciple was also a doctor?

Answer 1

It was Luke. That is one of the reasons why the story of Jesus's birth is so detailed in his gospel. He was interested in that since he was a doctor. Luke is not only Paul's Physician, but also Paul's travelling companion and biographer (as he apparently wrote the book of Acts).

Thus, as Paul's Physician he had first hand knowledge of the events he describes in Acts, and, as elsewhere in his writings, they have been demonstrated to be historically accurate, with the attention to detail one would expect from one experienced in observing the human condition, thus applied to history.

* for the interest of full disclosure; It is almost universally agreed that the author of Acts also wrote the Gospel of Luke. The traditional view is that both the two books were written c.60, though others view the book(s) as having been written at a later date, sometime between 70 and 100. 'Scholars are about evenly divided on whether [the] attribution to Luke [the companion of Paul] should be accepted as historical ...'.[2] http://en.wikipedia.org/wiki/Acts_of_the_Apostles Scholarship today is in wide agreement that both the Gospel and Acts have the same author.[7] Likewise, the traditional view of Lukan authorship is "widely held as the view which most satisfactorily explains all the data."[8] However, there is scholarly division concerning the traditional attribution that the text was written by Luke the companion of Paul (named in Colossians 4:14), division which R. E. Brown characterized as "evenly divided".[9] Scholars are also in disagreement concerning the date of the Gospel, arguing either for a pre- or post-70 date, though most all would agree that the text is a first century work. http://en.wikipedia.org/wiki/Gospel_of_Luke