The purpose of this study is to find out how well the HIV medication dolutegravir gets into different parts of the body: including blood plasma, special blood cells, and rectal tissue. Specifically, investigators want to compare how fast dolutegravir lowers the HIV viral load in these three different sites. In addition, investigators seek to learn if there are any differences in how dolutegravir acts in males and females. Results of this study will provide more information about HIV medications and their limitations. In the future, this could help create better HIV medications that can get into these hard-to-reach places and eventually cure HIV infection.