Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for sudden severe or rapidly worsening abdominal pain, especially when it is constant or accompanied by vomiting, bloody stool, fainting, confusion, cold or clammy skin, or a swollen and rigid abdomen.
These are not always emergencies, but they should not be ignored.
Treat sudden severe pain as an emergency rather than waiting for a routine appointment.
Do not wait for the pain to settle if you have been told you are at increased risk of intestinal ischemia.
Acute damage can progress even when early examination findings seem mild.
Arrange a prompt medical assessment for repeated pain after meals, unexplained food avoidance, ongoing diarrhea, or unintended weight loss.
If you already have chronic mesenteric ischemia, report returning symptoms promptly.
Every sign above is quoted from the sofidex article on Mesenteric artery ischemia. If you are not sure, err upward — it is always reasonable to be checked.