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 emergency care if tenesmus occurs with:
Heavy or continuing rectal bleeding
Fainting, confusion, severe weakness, or difficulty staying awake
Severe or rapidly worsening abdominal pain
A swollen abdomen with inability to pass stool or gas
Repeated vomiting, especially with abdominal swelling
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
Arrange same-day medical care if you have fever with rectal pain, pus-like discharge, bloody diarrhea, or signs of dehydration such as very little urine and marked dizziness.
Severe pain or swelling around the anus also needs prompt assessment because it may be an abscess.
3
Does any of this apply?
Book an appointment
Book a routine appointment if the feeling lasts more than several days, keeps returning, or interferes with sleep or daily activities.
You should also arrange an assessment for ongoing blood or mucus, an unexplained change in bowel habits, weight loss, or symptoms that began after pelvic radiation.
The article also says
Tell the clinician if symptoms followed anal sexual contact or if a sexually transmitted infection is possible.
This information helps them choose the right tests and can be discussed confidentially.
Every sign above is quoted from the sofidex article on Tenesmus. If you are not sure, err upward — it is always reasonable to be checked.