Oscar cant keep food down.

[BODYDUB]

My two use to do that every once in a while, and when it happened all I did was skip a day of feeding........

 

[Noddy]

yeah try different foods, like insects or something and see if that works, i wouldnt worry about it too much though unless he starts to lose weight or get stringy white poop

x2, try some mealworms and see how he reacts then.
My red suddenly refused the pellets and only ate worms and bugs for a year.
Now some months ago, he ate some Hikari algae wafers and started to eat the Hikari Cichlid pellets, and likes them very much now.

 

[Cecropia]

try soaking the pellets before you feed. Maybe they're too hard for him to chew into swallowable size?

 

[phillydog1958]

I've never had an oscar that would turn down a meal. Are you sure you're not overfeeding him? This is new to me, but it does not mean that your oscar is ill. Don't feed him for several days. You need to build up his appetite. Starve him.