Iron Deficiency Anaemia

Iron Deficiency Anaemia: Expert Assessment in Oxford, Banbury, Buckinghamshire, Warwickshire & North London

Iron deficiency anaemia (IDA) is one of the most common reasons adults are referred to a consultant gastroenterologist in the UK. As a Consultant Gastroenterologist and Nationally Accredited Bowel Cancer Screening Endoscopist, Dr Udit Mittal provides expert assessment and investigation of iron deficiency anaemia for patients across Oxfordshire, Banbury, Buckinghamshire, Warwickshire, the Cotswolds and North London.

This guide covers what iron deficiency anaemia is, the common gastrointestinal and non-gastrointestinal causes, which investigations are recommended, what happens when your gastroscopy and colonoscopy results are normal, and when you should seek specialist review.

What Is Iron Deficiency Anaemia?

Iron is essential for producing haemoglobin — the protein inside red blood cells that carries oxygen around the body. When the body’s iron stores become depleted, haemoglobin levels fall and iron deficiency anaemia develops.

In adults — particularly men and post-menopausal women — iron deficiency anaemia should be treated as a symptom rather than a diagnosis in itself. The British Society of Gastroenterology (BSG) recommends thorough investigation to identify the underlying cause, as it may signal a serious gastrointestinal condition including bowel cancer.

What Are the Symptoms of Iron Deficiency Anaemia?

Common Symptoms

• Fatigue and persistent lack of energy
• Breathlessness on exertion
• Dizziness or light-headedness
• Heart palpitations
• Headaches
• Reduced exercise tolerance
• Difficulty concentrating and brain fog

Less Common Symptoms

• Restless legs syndrome
• Hair loss
• Brittle or spoon-shaped nails (koilonychia)
• Craving ice or non-food substances (pica)
• Sore tongue (glossitis)
• Mouth ulcers
• Difficulty swallowing (dysphagia)

Some patients have surprisingly few symptoms despite significantly reduced iron stores. It is important not to dismiss ongoing fatigue or reduced exercise tolerance without a thorough assessment.

What Causes Iron Deficiency Anaemia?

Causes broadly fall into three categories: blood loss, reduced absorption, and increased demand.

Gastrointestinal Causes (Blood Loss or Malabsorption)

• Bowel (colorectal) cancer — the most important diagnosis to exclude
• Stomach cancer (gastric adenocarcinoma)
• Colon polyps — benign growths that can bleed
• Peptic ulcers — often caused by H. pylori infection or NSAID use, seen on gastroscopy
• Coeliac disease — causes malabsorption of iron in the small bowel
• Inflammatory bowel disease (Crohn’s disease or Ulcerative Colitis) — causes blood loss and malabsorption
• Angiodysplasia — abnormal blood vessels that bleed
• Cameron lesions — erosions in a hiatus hernia
• Rectal bleeding from haemorrhoids or other anorectal conditions

Non-Gastrointestinal Causes

• Heavy menstrual bleeding (menorrhagia) — the commonest cause in pre-menopausal women
• Pregnancy and breastfeeding (increased iron demand)
• Frequent blood donation
• Chronic kidney disease
• Heart failure
• Urinary tract blood loss (haematuria)
• Restrictive or plant-based diets with low dietary iron intake

Investigations for Iron Deficiency Anaemia

Investigation is tailored to the individual patient’s age, symptoms, risk factors and medical history.

Blood Tests

• Full blood count (FBC) — confirms anaemia and red cell size
• Serum ferritin — reflects iron stores (can be falsely elevated in inflammation)
• Serum iron and transferrin saturation
• Vitamin B12 and folate
• Coeliac antibodies (anti-TTG IgA and total IgA)
• Kidney and liver function tests
• Inflammatory markers (CRP, ESR)
• Thyroid function

Endoscopic Investigation

For most adults — particularly men and post-menopausal women — endoscopic investigation is recommended to exclude serious gastrointestinal pathology, including cancer.

• Gastroscopy (OGD) — examines the oesophagus, stomach and duodenum. Identifies peptic ulcers, coeliac disease, gastric cancer, Cameron lesions and other upper GI causes of blood loss.
• Colonoscopy — examines the entire colon, rectum and terminal ileum. Identifies bowel cancer, polyps, angiodysplasia and inflammatory bowel disease.

Both procedures are typically recommended together in patients with unexplained iron deficiency anaemia, in line with BSG guidelines. Dr Mittal is accredited by the Joint Advisory Group on GI Endoscopy (JAG) for both gastroscopy and colonoscopy.

What Happens After a Normal Gastroscopy and Colonoscopy?

If both a gastroscopy and colonoscopy are normal and iron deficiency persists, further evaluation of the small bowel may be required. This is because the small bowel is not accessible via standard endoscopy.

• Capsule endoscopy — the patient swallows a small camera capsule that photographs the entire small bowel. This is the preferred investigation for small bowel angiodysplasia, Crohn’s disease or small bowel tumours.
• CT or MR enterography — cross-sectional imaging of the small bowel used alongside or instead of capsule endoscopy depending on clinical circumstances.
• Push enteroscopy or balloon-assisted enteroscopy — allows direct endoscopic visualisation and treatment within the small bowel.

In some patients, particularly pre-menopausal women with heavy periods, a normal gastroscopy and colonoscopy is genuinely reassuring and no further endoscopic investigation is needed. Management focuses on iron replacement and treating the underlying non-GI cause.

Treatment of Iron Deficiency Anaemia

Treatment depends entirely on the underlying cause. Addressing the root cause is essential to prevent recurrence.

• Oral iron supplementation — ferrous sulfate, ferrous fumarate, or ferrous gluconate tablets are first-line. Best absorbed on an empty stomach with vitamin C.
• Intravenous (IV) iron infusion — used when oral iron is not tolerated, poorly absorbed, or when rapid correction is needed (e.g., before surgery).
• Treating the underlying cause — removing polyps at colonoscopy, treating H. pylori, managing coeliac disease with a gluten-free diet, or treating inflammatory bowel disease.
• Dietary advice — increasing iron-rich foods (red meat, lentils, spinach, fortified cereals) and vitamin C to aid absorption.

When Should You See a Gastroenterologist for Iron Deficiency Anaemia?

You should seek a consultant gastroenterology opinion if you experience any of the following:

• Confirmed iron deficiency anaemia in a man of any age
• Iron deficiency anaemia in a post-menopausal woman
• Persistent or recurrent iron deficiency despite oral supplementation
• Rectal bleeding or unexplained weight loss
• A change in bowel habit — including new diarrhoea or constipation
• Persistent abdominal pain or bloating
• Difficulty swallowing (dysphagia)
• A family history of bowel cancer or coeliac disease
• A positive FIT test result

Early specialist assessment allows prompt investigation, accurate diagnosis and appropriate treatment — reducing anxiety and the risk of serious pathology being missed.

Private Iron Deficiency Anaemia Assessment in Oxford, Banbury & Buckinghamshire

Dr Udit Mittal offers rapid-access private consultant appointments for patients with iron deficiency anaemia across Oxfordshire, Banbury, Buckinghamshire, Warwickshire, the Cotswolds and North London. Appointments are typically available within days, with onward endoscopy arranged promptly where clinically indicated.

As a Nationally Accredited Bowel Cancer Screening Endoscopist and JAG-accredited endoscopist, Dr Mittal personally performs all gastroscopy and colonoscopy procedures — ensuring continuity, expertise and a high-quality patient experience throughout your care.

Frequently Asked Questions

Can iron deficiency anaemia be a sign of cancer?

Yes. Iron deficiency anaemia — particularly in men and post-menopausal women — can be caused by slow, occult (hidden) bleeding from a bowel cancer or stomach cancer. This is why specialist investigation with endoscopy is recommended. However, most causes of iron deficiency anaemia are benign and treatable.

Is a gastroscopy or colonoscopy done first?

Both are typically recommended together. In some cases — particularly in patients with predominantly lower GI symptoms — colonoscopy may be prioritised. The decision is made on an individual basis following your consultant appointment.

What if my iron levels keep dropping despite taking iron tablets?

Persistent or recurrent iron deficiency despite adequate oral iron supplementation is a red flag and requires further investigation. Causes include ongoing blood loss, malabsorption (e.g., coeliac disease), or inadequate iron absorption due to medication interactions.

How long does it take for iron levels to recover?

With appropriate iron replacement, haemoglobin typically begins to recover within 4 to 6 weeks. However, replenishing iron stores (ferritin) can take 3 to 6 months of continued supplementation.

Medical Disclaimer

The information on this page is intended for general educational purposes only. It does not constitute medical advice and should not replace a personalised consultation with a qualified healthcare professional. If you are experiencing symptoms such as rectal bleeding, unexplained weight loss, persistent abdominal pain or difficulty swallowing, please seek prompt medical attention from your GP or a specialist. Do not delay seeking medical advise because of information you have read on this website.

Further Information

To book a private appointment with Dr Udit Mittal, please visit the appointments page or contact the practice directly.