Gastritis Support Group
Gastritis is a medical term for inflammation of the lining of the stomach. It means that white blood cells move into the wall of the stomach as a response to some type of injury. Gastritis has many underlying causes, from infection with the bacterium H. pylori, bile reflux, or excessive consumption of alcohol or certain foods or drugs like aspirin.
Just because something is natural does not mean it is safe.
I don't know the laws or the general stance in the US regarding I ingestion of essential oils, but in the UK it is definitely not a common practice.
I am certain essential oils should only be taken internally under the guidance of a qualified practitioner.