Acute mesenteric ischaemia: a case-based approach

The presentation

Imagine an older adult with an irregular heartbeat who suddenly develops severe, constant tummy pain that comes on over minutes. The pain is intense and central, yet when a doctor gently presses the abdomen early on it can seem surprisingly soft and not especially tender — a mismatch often summed up as pain out of proportion to the examination. The person may feel sick, vomit, have an urgent need to open their bowels, or pass blood. As hours pass and the bowel is starved of blood, they become more and more unwell, the abdomen becomes swollen, rigid and very tender, and signs of serious illness set in. This sudden, severe, poorly explained tummy pain in someone at risk is the picture that should prompt urgent action rather than waiting to see if it eases.

Why it happens and why it is dangerous

The bowel, like any organ, needs a constant blood supply. In acute mesenteric ischaemia this supply is suddenly blocked — most often by a clot that has travelled from the heart and lodged in an artery feeding the gut, or by a clot forming in a narrowed artery or vein. Starved of oxygen, the bowel wall is injured within hours and, if the blockage is not relieved, the tissue dies. A dead segment of bowel leaks its contents and bacteria into the abdomen and bloodstream, causing overwhelming infection and shock. This is why the condition is so lethal if missed: the window to restore blood flow and save the bowel is short. Treatment is a hospital emergency and may involve urgent scans, medicines to break up or prevent clots, procedures to reopen the artery, and surgery to remove any dead bowel.

When to call 999

Call 999 or go straight to A&E for sudden, severe tummy pain that is constant and does not settle, especially if it seems far worse than expected, or if there is pain with vomiting, blood in the stool, a swollen, hard or very tender abdomen, or someone becoming pale, sweaty, faint or confused. The urgency is greater still in people with risk factors such as an irregular heartbeat, previous clots, heart disease or hardened arteries. Do not wait to see if it passes, and do not put severe sudden tummy pain down to simple indigestion or a bug, particularly in older people. While waiting for the ambulance, keep the person still, do not give food or drink in case surgery is needed, and note when the pain began and how it has changed.

Who is more at risk

Acute mesenteric ischaemia becomes more likely with age and with conditions that make clots or narrowed arteries more likely. An irregular heart rhythm called atrial fibrillation is an important risk, because clots can form in the heart and travel to the gut arteries. Other risks include previous heart attacks or heart failure, hardened, narrowed arteries elsewhere in the body, previous blood clots, some clotting disorders, and recent major illness or surgery. People who already get a cramping tummy pain after meals from narrowed gut arteries — a kind of warning sign — may be at higher risk of a sudden blockage. Knowing these risks matters because it lowers the threshold for taking sudden severe tummy pain seriously: in an at-risk person, this symptom should be treated as a possible emergency until proven otherwise.

The safe pathway

The practical rule is that not all tummy pain is an emergency, but certain patterns must never be ignored. Mild, familiar, settling tummy aches — from wind, a tummy bug or period pain — can usually be managed at home with self-care, seeking routine advice if they persist. However, sudden, severe, constant tummy pain, pain that is out of proportion to how the abdomen feels, pain with vomiting or blood in the stool, or a rigid, very tender abdomen is an emergency: call 999 or go to A&E. This is especially important in older people and anyone with heart rhythm problems, previous clots or artery disease. Acute mesenteric ischaemia is uncommon, but because the bowel can only survive a short time without blood, early hospital assessment saves lives and bowel.