J. Paul Getty Grandson -- Massive Blood Loss Before Death ... Ulcer Suspected

J. Paul Getty's grandson Andrew Getty died from a massive bleed from his intestines ... that's the preliminary conclusion of the L.A. County Coroner.

TMZ broke the story ... 47-year-old Getty was found dead in his L.A. home Tuesday, laying in the bathroom with blood around his rectal area.

Law enforcement sources tell TMZ ... Getty lost a full liter of blood, and so far it looks like an ulcer.

Getty had been complaining of serious stomach pain for several days before his death and made an appointment to see a doctor, which was scheduled for the day after he died. He had been suffering from severe stomach cramps.

Authorities believe Getty was trying to make it to the bathroom to relieve the pressure when he collapsed.