Small Bowel MRI Scan: Complete Guide

A small bowel MRI (also called MRI enterography or MRE) is a specialised imaging technique used to visualise the small intestine in detail. It's the gold standard for assessing inflammatory bowel conditions, particularly Crohn's disease, without the radiation exposure of CT. This guide covers everything you need to know about getting a small bowel MRI in the UK.

What a Small Bowel MRI Shows

Small bowel MRI provides detailed images of the entire small intestine — duodenum, jejunum, and ileum — as well as the surrounding mesentery and lymph nodes. It can detect:

• Crohn's disease activity — wall thickening, ulceration, mucosal enhancement, and stricturing
• Bowel wall inflammation — oedema and hyperaemia in the intestinal wall
• Strictures and narrowing — areas where the bowel lumen is constricted
• Fistulae — abnormal connections between the bowel and other organs or the skin surface
• Abscesses — collections of pus near the bowel
• Small bowel tumours — including lymphoma, carcinoid tumours, and adenocarcinoma
• Complications of coeliac disease — including refractory disease and lymphoma risk
• Mesenteric abnormalities — enlarged lymph nodes or vascular issues

When You Might Need a Small Bowel MRI

A small bowel MRI may be recommended if you experience:

• Chronic abdominal pain, particularly in the lower right abdomen
• Unexplained diarrhoea lasting more than four weeks
• Rectal bleeding or blood in your stools
• Unexplained weight loss or poor appetite
• Iron deficiency anaemia without an obvious cause
• Known Crohn's disease requiring monitoring or assessment of disease extent
• Suspected small bowel obstruction
• Abnormal blood markers suggesting intestinal inflammation (e.g. raised CRP or faecal calprotectin)

Small bowel MRI is particularly important for younger patients with suspected inflammatory bowel disease, as it avoids the radiation exposure of CT scanning.

How to Prepare for a Small Bowel MRI

Preparation for a small bowel MRI is more involved than a standard MRI:

• Fasting: You'll typically need to fast for 6 hours before the scan
• Oral contrast: You'll drink approximately 1–1.5 litres of a contrast agent (often mannitol or Klean-Prep) over 45–60 minutes before the scan. This distends the bowel loops and improves image quality
• Anti-spasmodic injection: You may receive an injection of Buscopan (hyoscine butylbromide) to reduce bowel movement during scanning
• IV contrast: Gadolinium contrast is usually administered through a cannula during the scan
• Clothing: Wear comfortable, metal-free clothing
• Allergies and medical history: Inform the team about any allergies, kidney problems, or implants

What to Expect During the Scan

A small bowel MRI typically takes 45–60 minutes:

1. Arrival: Plan to arrive 60–90 minutes early to allow time for drinking the oral contrast
2. Oral contrast: You'll drink the preparation at timed intervals — the team will guide you
3. Safety check: Complete the MRI safety questionnaire and change into a gown if needed
4. Positioning: You'll lie face down (prone) or on your back on the scanner table
5. Anti-spasmodic: An injection to slow bowel movement is given just before or during the scan
6. Scanning: Multiple sequences are acquired. You'll hear loud sounds — ear protection is provided
7. IV contrast: Gadolinium is injected partway through for enhanced images
8. Completion: You can eat and drink normally afterwards

The oral contrast can taste unpleasant and may cause mild bloating or loose stools afterwards, but these effects resolve quickly.

Small Bowel MRI Cost in the UK

A private small bowel MRI in the UK typically costs between £500 and £1,000. NHS scans are free but can involve major waiting times, especially for non-urgent referrals.

Lola Health offers small bowel MRI scans through our network of 150+ UK scanning centres via scan.com. Results are reported by a consultant radiologist within 7–10 working days. View our small bowel MRI scan for pricing and booking.

Small Bowel MRI and Blood Testing

Blood tests play a important role in identifying when a small bowel MRI might be needed. Key markers include:

• C-reactive protein (CRP) — elevated in active Crohn's disease and other inflammatory conditions
• Full blood count — may reveal iron deficiency anaemia (low haemoglobin, low MCV), suggesting chronic blood loss or malabsorption
• Ferritin and iron studies — low ferritin can indicate malabsorption from small bowel disease
• Vitamin B12 and folate — deficiencies may suggest terminal ileum disease (B12 is absorbed here)
• Albumin — low levels can indicate protein-losing enteropathy or severe inflammation
• Liver function tests — may be abnormal in primary sclerosing cholangitis, which can accompany IBD

Start with a Lola Health blood test to check your CRP, ESR, faecal calprotectin, iron studies, and vitamin B12. If results suggest further investigation, a small bowel MRI can provide the structural detail your blood results can't show. Peak Insights 70 covers these markers across 70 biomarkers.

If your blood results show raised inflammatory markers, unexplained anaemia, or nutrient deficiencies, a small bowel MRI can help identify the underlying bowel pathology.

Explore Lola Health blood tests to check your inflammatory markers and nutritional status.

Considering a broader check? Read our full body MRI scan guide to see what a complete MRI screening covers, or explore the Peak 70 + Full Body MRI bundle for the most thorough health check available.

Frequently Asked Questions

Is a small bowel MRI uncomfortable?

The scan itself is painless, though drinking the oral contrast can be unpleasant. Some people experience mild bloating or nausea. The anti-spasmodic injection may cause temporary blurred vision or dry mouth.

How long does a small bowel MRI take?

The scan takes 45–60 minutes, but you should allow 2–3 hours in total including the oral contrast preparation time.

Can a small bowel MRI detect cancer?

Yes. MRI can identify small bowel tumours, including lymphoma, carcinoid, and adenocarcinoma, and assess their extent. However, it's most commonly used for inflammatory conditions.

Is it better than a colonoscopy?

They examine different areas. Colonoscopy visualises the large bowel and terminal ileum, while small bowel MRI images the entire small intestine. They're often complementary, not competing, investigations.

Can I drive after the scan?

If you receive Buscopan, it can cause temporary blurred vision. Wait until your vision returns to normal before driving — usually 15–30 minutes.

Do I need a referral?

For a private scan through Lola Health, you don't necessarily need a GP referral, though having clinical context helps the radiologist provide a more targeted report.

How often should I have a small bowel MRI?

For Crohn's disease monitoring, your gastroenterologist will advise — typically annually or when symptoms change. MRI is preferred for monitoring because it's radiation-free.

Book Your Small Bowel MRI Scan

If you're experiencing persistent digestive symptoms or need to monitor an existing bowel condition, a small bowel MRI gives you detailed answers without radiation exposure.