Dexmethylphenidate, sold under the trade names Focalin among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It is in the phenethylamine and piperidine classes of medications. It is the active dextrorotatory enantiomer of methylphenidate.
1 Some allergies cause digestion problems as well. There are also times when you may feel nauseous after every meal. Nausea after meals can also be accompanied with other allergic symptoms, such as, hives or rashes.  Psychological â Sometimes, nausea after eating may also occur due to psychological factors.
I feel nauseous almost every morning too but it started when I started taking zoloft so I'm guessing it's one of the side effects. Also, I don't know what kind of pain you feel in your stomach but I have stomach problem with acid. This happens every time I stress out and it involves food My pain is sharp and is right under my chest bone. But if you have burning feeling in your stomach and chest area it might be heartburn.