The first thing we tried was manggis hutan (wild mangosteen). It actually looked like a ballooned duku/langsat. Even tasted slightly like one, but the look and texture is very similar to manggis (mangosteen).
The next we took was pulasan. Well of course I have tried pulasan, but I found another type which is dark purple. The seller said it is called pulasan hitam (doesn't sound convincing to me). They tasted very much like rambutan, but the red pulasan is more juicy. I find the pulasan hitam softer and fragrant more towards lychee.
The last and biggest fruit I have pointed is called bambangan (if I spelt it right). Very easy to peel. When I first bit into the flesh, it tasted very much like mango, but with slightly more fibre. But the after taste that dwells in my tongue after I swallowed the fruit smelled like nangka (jackfruit).
Interesting fruits that you should try if you were there. And no, I did not suffer any stomach ache, so no worries :)