(Cover) - EN Showbiz - Zach Galifianakis was worried he might accidently get a sex change after learning the Hangover 2 was being set in Bangkok.

The American comedian-and-actor returns as Alan Garner in the follow-up to the hugely successful film, which appeared in cinemas in 2009.

The 41-year-old was concerned there was a possibility he would return home altogether different from Thailand, which has a reputation for unusual customs, after hearing the country was central to the film.

I was afraid I might accidentally get a sex change. I dont think that happened, he joked to Empire magazine.

But his co-star, Bradley Cooper, was thrilled by the prospect of the movies location. He had heard that it was a place where extreme parties happen regularly. [I was] over the moon, he explained. From my little knowledge of Bangkok, I thought it sounded like Vegas on steroids.

However, the reality was a little different. The 36-year-old said the country was totally different to what the crew expected leaving many of them unwell.

It didnt feel like wed started the movie til we were in Bangkok things started getting crazy, people started getting sick. We needed to get it into our blood. Literally. On a bacterial level, Bradley said. (C) Cover Media