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
Seek urgent or emergency help for:
Heavy or continuous rectal bleeding, especially with faintness or weakness
Severe abdominal pain or swelling with vomiting
Inability to pass stool or gas, which may indicate bowel obstruction
Sudden chest pain, severe breathlessness, confusion, or collapse
Fever with marked illness during chemotherapy or other treatment that lowers immunity
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
If you have already been treated, report new bleeding, worsening bowel problems, persistent pain, unexplained weight loss, or new breathing symptoms promptly.
Follow the urgent-care instructions provided by your cancer service, as some treatment complications need assessment the same day.
3
Does any of this apply?
Book an appointment
Arrange a medical assessment if you develop rectal bleeding, a persistent change in bowel habits, unexplained weight loss, ongoing pelvic discomfort, or symptoms of anaemia.
These symptoms often have a non-cancerous cause, but they should not be ignored.
Routine concerns about diet, bowel frequency, sexual function, stoma equipment, or ongoing side effects can usually be discussed during planned follow-up or with your treatment team.
And for anyone, someone who:
has noticed a lump, a mole that has changed, or unexplained weight loss
Every sign above is quoted from the sofidex article on Rectal cancer. If you are not sure, err upward — it is always reasonable to be checked.