I've had stomach pain & loose stools for 3 wks.had an endoscopy and found 2 erythematous spots at the atrum.what does this mean?should i be concerned?

Not necessarily: It means the endoscopist saw some reddish coloration of the lining of the distal stomach. This may or may not be significant. The finding can indicate gastritis (inflammation of the stomach lining) due to an infectious or other process. But the observation of "erythema" is subjective(the area may seem normal to another MD) and a biopsy of the area may be normal. Gastritis is a histologic diagnosis

Well: Most people stomachs have a few red spots on them could be mile gastritis. Probably not significant with the information we have. But for specific diagnosis treatment advice you need to talk to the Doctor Who did the scope test and see if there any biopsy results