This has happened before but she never had the rectal bleeding. This is her second episode.
She was told not to have a drop back then.
Vomiting blood as well as rectal bleeding is very serious. Have the doctors done an endoscopy and colonoscopy yet? This sounds like she has varices in her esophagus from her alcoholism, as well as varices/hemorrhoids from the rectal bleeding. If she continues vomiting blood and rectal bleeding, and they can't keep her hemoglobin up with blood transfusions, then it could be very likely near the end. if the hemoglobin drops low enough, she could have a heart attack. Or she could basically bleed to death if the vomiting does not stop. Hence, to answer your question, this is very serious. Do you know what your mother's wishes are regarding end-of-life care?
well, what are your mom's wishes? does she want to be resuscitated? have the doctors decided to do any interventions? is your mom alert currently?