What Causes Intestinal Ischaemia?

Intestinal Ischemia Explained: Causes, Warning Signs & Care

Our digestive system requires a constant, rich blood supply to function properly. Like the heart and brain, the intestines depend on uninterrupted oxygenated blood flow. When this flow is reduced or blocked, it leads to a serious condition known as intestinal ischaemia.

This condition may affect the small intestine, the large intestine (colon), or both and may occur suddenly (acute) or gradually (chronic) over time. If left untreated, it can lead to tissue death, infection, and life-threatening complications.

Below, we explore the various causes of intestinal ischaemia, how it develops, its symptoms, prevention strategies, and available treatment.

What are the causes of intestinal ischaemia?

Several underlying conditions and risk factors contribute to the development of intestinal ischaemia. These include arterial (oxygen-rich blood supply) and venous (blood drainage) issues:

1.  Arterial Embolism

A blood clot or other material (like cholesterol plaque) can break off from the heart or major arteries and travel to the intestinal arteries, suddenly blocking blood flow. Acute mesenteric ischaemia is a common cause, typically occurring in individuals with:

• Atrial fibrillation
• Recent heart attack
• Valvular heart disease

2.  Arterial Thrombosis

Instead of travelling from elsewhere, a clot can form directly in the arteries that supply the intestines. This usually develops over time due to:

• Atherosclerosis (hardening of the arteries)
• High cholesterol
• Smoking
• High blood pressure

3.  Non-Occlusive Mesenteric Ischaemia (NOMI)

In this form, there is no actual blockage. Instead, blood flow is reduced due to:

• Very low blood pressure (shock, heart failure, severe infection)
• Use of certain medications (like vasoconstrictors)
• Critical illness, especially in ICU patients

4.  Mesenteric Venous Thrombosis

A blood clot can also occur in veins that drain blood from the intestines. This slows blood drainage, leading to swelling, reduced blood flow, and tissue damage. Causes include:

• Blood clotting disorders
• Pancreatitis
• Abdominal infections or trauma
• Liver disease
• Oral contraceptive use

5.  Ischaemic Colitis

This milder and more common type typically occurs in older individuals. It can be caused by:

• Low blood pressure
• Dehydration
• Certain medications (diuretics, digitalis, chemotherapy drugs)
• Narrowing of the colon blood vessels
• Bowel surgery or radiation therapy

What are the symptoms of intestinal ischaemia?

Symptoms vary based on the type and severity of ischaemia. These include:

Acute Mesenteric Ischaemia:

• Sudden severe abdominal pain (often out of proportion to physical exam)
• Nausea and vomiting
• Urgent need to pass stool
• Bloody stools (later sign)
• Rapid heart rate
• Confusion or lethargy (in advanced cases)

Chronic Mesenteric Ischaemia:

• Recurrent dull abdominal pain 30–60 minutes after eating (intestinal angina)
• Weight loss (due to fear of eating)
• Bloating
• Diarrhoea

Ischaemic Colitis

• Cramping or mild abdominal pain, usually on the left side
• Bloody or maroon-coloured stools
• Urge to defecate frequently

What are the treatment options for intestinal ischaemia?

Treatment depends on the type and severity of ischaemia. It may include both surgical and non-surgical methods. They may include:

1.  For Acute Mesenteric Ischaemia (Acute Bowel Ischaemia):

• Emergency surgery to remove clots or bypass blocked arteries
• Angioplasty with stenting (minimally invasive)
• Anticoagulants (blood thinners)
• Broad-spectrum antibiotics to prevent infection
• Bowel resection if part of the intestine is dead

2.  For Chronic Mesenteric Ischaemia:

• Balloon angioplasty and stenting
• Surgical bypass of narrowed arteries
• Dietary modifications (small, frequent meals)

3.  For Ischaemic Colitis:

• Supportive Care – rest, IV fluids, antibiotics
• Avoiding vasoconstrictive medications
• Bowel rest
• Surgery, only if there’s severe tissue death, gangrene, or perforation

How Can You Prevent Intestinal Ischaemia?

Here are the steps to reduce the risk of intestinal ischaemia:

1. Manage Heart Health: Control blood pressure, cholesterol, and arrhythmias. Regular check-ups and cardiac screenings can help detect early symptoms and prevent complications.
2. Quit Smoking: Smoking damages blood vessels and speeds up atherosclerosis. Even exposure to second-hand smoke may increase risk, so complete avoidance is recommended.
3. Stay Hydrated: This is especially essential for older adults and during illness. Proper hydration helps maintain adequate blood volume and pressure, ensuring optimal circulation to the intestines.
4. Exercise Regularly: Improves circulation and reduces vascular risks. Activities like walking, swimming, or yoga support cardiovascular health and help prevent blood clot formation.
5. Monitor Medications: Avoid vasoconstrictors and high-risk drugs if you’re prone to ischaemia. Always consult a healthcare provider before starting or discontinuing any prescriptions.
6. Control Diabetes: High blood sugar levels can damage blood vessels over time. Consistent glucose monitoring and a balanced diet can significantly reduce vascular complications.
7. Seek Treatment for Clotting Disorders: If diagnosed with conditions like Factor V Leiden or antiphospholipid syndrome, follow prescribed treatment therapies to reduce the risk of clot formation.

Intestinal ischaemia is a potentially life-threatening condition that arises when the blood supply to the intestines is reduced or blocked. Causes range from sudden blood clots to chronic artery narrowing and low blood pressure events. While symptoms can vary from mild to severe, prompt diagnosis and timely treatment are crucial for recovery.

Being aware of the warning signs—such as post-meal abdominal pain, unexplained weight loss, or sudden severe pain-can help detect the condition early. Managing risk factors like smoking, heart disease, and dehydration plays a significant role in prevention.

At Star Health, we believe in proactive healthcare. If you or your loved ones experience persistent digestive discomfort or belong to a high-risk group, consult a healthcare provider promptly. Early intervention saves lives and improves outcomes.