Lactose Intolerance

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Lactose is a protein found in most dairy products e.g. milk and cheese, and intolerance is a common digestive ailment. Symptoms may include nausea, bloating, excessive wind, diarrhoea and abdominal cramps. Lactose intolerance presents on a spectrum of severity, from those who can consume small amounts without becoming unwell, to those who cannot even tolerate milk in a cup of tea.

If you think you may be experiencing symptoms of lactose intolerance, it may be helpful to keep a diary of the food you eat for two weeks before you visit your GP. At Midland Health, we can provide expert advice for diagnosing and managing lactose intolerance, including asking the right questions to ensure your symptoms aren’t caused by something else e.g. Irritable Bowel Syndrome or inflammatory bowel conditions.

Lactose Intolerance Causes

Lactose intolerance is caused by the inability of the body to process milk and dairy products due to the lack of lactase in the bowel. Lactase is an enzyme usually found in the intestines, which breaks down lactose. Without it, the normal digestive process is interrupted and lactose remains in the intestines, fermenting over time. The inability of the organism to break down lactose is referred to as lactose intolerance. 

Lactose tolerance can reduce with age, so it is not uncommon for people who have had no issues with dairy products in the past to become lactose intolerant. In fact, the two most common causes of lactose intolerance develop later in life.

  • Primary lactase deficiency begins to develop from the age of 2-3 onwards and refers to the gradual reduction of lactase in your bowl until lactose intolerance is developed 
  • Secondary lactase deficiency is caused by damage to the lining of the bowel caused by diseases, such as gastroenteritis or coeliac disease. Usually, this type of lactose intolerance is only temporary and you will get back to normal as soon as the condition that caused the deficiency is cured

Lactose intolerance in children is rare and can either be triggered by one of the following two causes:

  • Congenital lactase deficiency - a birth defect where the baby has no lactose in their system at all. This condition causes diarrhoea and prevents the baby from gaining healthy weight. If you notice such symptoms, speak to your doctor immediately. 
  • Developmental lactase deficiency - a condition found in prematurely born babies where lactase hasn’t developed yet. Babies usually grow out of this type of lactose intolerance as more lactase is produced in the body

 If you suspect you may have started exhibiting symptoms of lactose intolerance, book a GP appointment at Midland Health to discuss your symptoms with a doctor. 

Lactose Intolerance Symptoms

You may begin to suspect that you are lactose intolerant if you notice the appearance of certain symptoms within a few hours of consuming dairy products. The symptoms of lactose intolerance that you may experience include: 

  • Bloating and gas
  • Diarrhoea 
  • Stomach cramps
  • Stomach rumbling 
  • Nausea and vomiting 

Depending on the severity of your lactose intolerance and the amount of lactose that you have consumed, the severity of the symptoms may vary too. 

It’s useful to make a note of your symptoms you experience as well as the type and amount of dairy you have consumed. This could help your doctor make a diagnosis later on. 

Lactose Intolerance Diagnosis

Lactose intolerance diagnosis in adults can be confirmed by doing a number of lactose intolerance tests, including a lactose tolerance blood test or a biopsy of the small bowel (where a sample of your bowel tissue is tested in a laboratory). 

  • Lactose Intolerance Blood Test: You will be asked to drink lactose in liquid form. Two hours later a blood sample will be taken. If the glucose levels in your blood aren’t high enough, this would indicate that your body is not processing lactose correctly. 

Children may not be eligible for these tests, so a stool acidity test may be performed instead. It works by examining stool samples to detect traces of the acid created during the fermentation of lactose in the intestines. 

Lactose Intolerance Treatment

While there is no cure for lactose intolerance, symptoms may be relieved with certain medication, but most people choose to manage the symptoms by making changes to their diet. 

The first step is to reduce the consumption of products that contain lactose, such as dairy, milk and some types of bread. Many of the products that include lactose can be supplemented by lactose-free alternatives, such as soya milk, almond milk, hazelnut milk, coconut milk and lactose-free cow’s milk. 

As milk and other dairy products contain vitamins, calcium and proteins, your GP may also advise you to take vitamin D tablets and other supplements to achieve the correct nutritional balance. It may also be recommended to add more lactose-free, calcium-rich foods to your diet. 

In terms of medication, you could be prescribed lactase substitutes in the form of tablets or drops which can be taken with your meals to help you digest lactose correctly and avoid the unpleasant effects of lactose intolerance.


Cow's Milk Components Allergy Blood Test


Milk and Milk Proteins Allergy Blood Test


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Can you suddenly become lactose intolerant?

Yes, it is possible to become lactose intolerant later in life.

Are milk allergy and lactose intolerance the same thing?

No, a milk allergy is an immune response to a special protein contained in milk, so even a drop of milk could cause an allergic reaction. This could be a life-threatening condition. Whereas lactose intolerance is caused by the inability to digest lactose and albeit having unpleasant symptoms, it is not life-threatening.

Is there anything else that could cause the same symptoms as lactose intolerance?

Yes, conditions, such as Irritable Bowel Syndrome and other inflammatory bowel conditions, exhibit similar symptoms so your GP may prescribe various tests to rule those out and reach the correct diagnosis.

Do I need to stop eating dairy products before my GP visit?

No, you should eat normally and make a note of your symptoms in a food diary. Ideally, you should have two weeks’ records in your food diary when you go to your appointment to give your doctor more information to work with.

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