Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Go to an emergency department or call emergency services if you have:
A large amount of rectal bleeding or bleeding that continues
Fainting, confusion, marked weakness, or cold clammy skin
Sudden severe or rapidly worsening abdominal pain
A hard, very tender, or increasingly swollen abdomen
Repeated vomiting with an inability to pass stool or gas
Severe pain with fever or signs of collapse
These features may indicate major blood loss, intestinal obstruction, perforation, or another serious abdominal condition.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek urgent same-day medical assessment for blood in the stool, black sticky stool, new persistent abdominal pain, or symptoms of anaemia such as unusual tiredness, breathlessness, dizziness, or pale skin.
These symptoms have many possible causes and need proper assessment.
3
Does any of this apply?
Book an appointment
Discuss it during routine follow-up unless new symptoms develop.
The article also says
A Meckel diverticulum found by chance without symptoms is not usually an emergency.
Every sign above is quoted from the sofidex article on Meckel diverticulum. If you are not sure, err upward — it is always reasonable to be checked.