It sounds like you got sick fairly quickly. In cases where a person develops nausea and vomiting
in a very short period of time, we can usually attribute it to either an infection, something you ate, or something going on in your GI tract independent of those two. If the spinach you ate was infected with bacteria, then this could have caused you to become sick very quickly from a toxin that some bacteria produce. This is the so-called food poisoning. Another possibility is that you are allergic to spinach, though a food allergy usually causes itching and hives.
It is also possible that the sickness you had was not due to the spinach at all, and it is just a coincidence that you ate this spinach last night. Viruses that infect the GI track and cause nausea and vomiting are very common. You may have caught this virus a few days back and you are just now feeling sick. Finally, your abdominal pain and vomiting could be due to something else such as a stomach ulcer.
I suggest that you schedule an appointment with your primary care physician
. He or she can take a more detailed history of your illness and perform a thorough physical exam. Likely your doctor
will be able to figure out what happened to you.