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 constipation occurs with severe or worsening belly pain, repeated vomiting, marked abdominal swelling, or inability to pass gas.
These may indicate a blocked bowel.
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 medical advice the same day for fever with significant belly pain, black or tar-like stool, substantial rectal bleeding, or rapidly worsening symptoms.
Contact a healthcare professional promptly if a child has constipation with vomiting, a swollen belly, significant pain, poor feeding, or reduced energy.
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if constipation:
Does not improve with reasonable self-care
Keeps returning or affects daily activities
Is a new or unexplained change in your usual pattern
Occurs with unplanned weight loss, ongoing bleeding, or persistent pain
Requires regular laxatives
Begins after starting a medicine
The article also says
Babies and young children need age-specific advice.
Every sign above is quoted from the sofidex article on Constipation. If you are not sure, err upward — it is always reasonable to be checked.