Coeliac Disease: Symptoms, Testing and When to See a GP in the UK

Coeliac disease is a serious autoimmune condition, not a simple food allergy or intolerance. In people with the condition, the immune system mistakes substances found in gluten—a protein found in wheat, barley, and rye—as a threat. This causes the body to attack its own tissues, specifically the small intestine.

According to Coeliac UK, the condition affects approximately 1 in 100 people in the United Kingdom, though many remain undiagnosed. When a person with coeliac disease consumes gluten, the tiny finger-like projections in the gut, known as villi, become inflamed and flattened. This damage prevents the body from absorbing essential nutrients from food, leading to malabsorption and various long-term health issues.

The symptoms of coeliac disease can range from mild to severe and often mimic other digestive concerns like Irritable Bowel Syndrome (IBS). In the UK, NICE (National Institute for Health and Care Excellence) guidelines suggest that clinicians should consider coeliac disease for anyone presenting with persistent unexplained gastrointestinal symptoms.

Digestive Symptoms

• Diarrhoea: This is often the most common symptom, involving foul-smelling stools that may be difficult to flush (steatorrhoea).
• Bloating and Flatulence: Persistent swelling of the abdomen after eating.
• Stomach Pain: Cramping or general abdominal discomfort.
• Constipation: While diarrhoea is common, some patients experience infrequent bowel movements.

Non-Digestive Symptoms

• Fatigue: Often resulting from anaemia (iron deficiency).
• Unintentional Weight Loss: Due to the inability to absorb calories and nutrients.
• Dermatitis Herpetiformis: An itchy, blistering skin rash linked to gluten consumption.
• Mouth Ulcers: Recurrent sores in the mouth can be a sign of nutritional deficiencies.

If you suspect you have coeliac disease, it is vital that you do not remove gluten from your diet before testing. The blood tests used by the NHS look for antibodies that the body produces in response to gluten. If you stop eating gluten, these antibody levels will drop, potentially leading to a false-negative result.

The standard UK testing pathway usually involves:

• Initial Blood Test: Checking for Total IgA and tissue transglutaminase antibodies (tTG).
• Endoscopy and Biopsy: If the blood test is positive, a specialist (gastroenterologist) may perform an endoscopy to take a small sample of the gut lining to confirm damage.

NICE guidance also recommends testing for people with related conditions, such as Type 1 diabetes or autoimmune thyroid disease, as these increase the risk of developing coeliac disease.

Navigating gut health can be confusing, especially when symptoms are intermittent. If you are struggling with persistent bloating, changes in bowel habits, or unexplained tiredness, you can speak to a GP online for an initial assessment. An online doctor can review your symptoms, discuss your family history, and advise on whether a coeliac screening is appropriate.

Consulting an online GP is a convenient way to get evidence-based advice without waiting weeks for an in-person appointment. They can explain the NHS diagnostic criteria, provide guidance on how to maintain a gluten-containing diet for testing, and help you understand the next steps in your care pathway. If your symptoms suggest other issues like IBS or inflammatory bowel disease, they can help differentiate these concerns.

There is currently no cure for coeliac disease; the only effective treatment is a strict, lifelong gluten-free diet. Once gluten is removed, the gut lining usually begins to heal, and symptoms typically improve within a few weeks, though full recovery of the villi can take months or years.

UK patients diagnosed with coeliac disease are often eligible for support, including:

• Dietetic Support: Referral to a registered dietitian to ensure nutritional needs are met.
• Gluten-Free Prescriptions: In some areas of the UK (though increasingly limited in England), basic gluten-free staples like bread and flour may be available on prescription.
• Annual Reviews: Regular check-ups to monitor bone health (DEXA scans) and nutritional markers.

It is important to be aware of 'hidden' gluten in products like soy sauce, beer, and even some medications. Cross-contamination in kitchens is also a significant risk that patients must manage.

Leaving coeliac disease untreated can lead to long-term health complications due to chronic inflammation and malabsorption. These include osteoporosis (weakened bones) because of a lack of calcium and Vitamin D absorption, and iron deficiency anaemia. In rare cases, untreated coeliac disease is associated with an increased risk of certain types of small bowel cancers. However, following a strict gluten-free diet significantly reduces these risks and allows most people to live a healthy, symptom-free life.