Malabsorption Syndrome: Symptoms, Causes and Diet

Malabsorption syndrome means your gut cannot properly absorb nutrients from food, such as fats, protein, carbohydrates, vitamins or minerals. It is not a single disease but a sign of an underlying problem, like coeliac disease, Crohn’s disease or a pancreas condition. Common symptoms include ongoing diarrhoea, bloating, weight loss and tiredness.

Because the body is missing out on nutrients, malabsorption can lead to deficiencies that affect your energy, bones, blood and immune system. The good news is that once the cause is found and treated, many people feel much better. This guide covers the symptoms, causes, diagnosis and the role of diet.

What is malabsorption syndrome?

When you eat, your stomach, pancreas, liver and small intestine work together to break food down and move nutrients into your bloodstream. Most absorption happens in the small intestine, which is lined with tiny finger-like projections called villi.

Malabsorption happens when something interferes with this process. Food may not be broken down properly, the gut lining may be damaged, or part of the bowel may be missing or bypassed. Some people have trouble absorbing many nutrients, while others struggle with just one, such as lactose or vitamin B12.

What are the symptoms of malabsorption syndrome?

Symptoms depend on which nutrients are not being absorbed and what is causing the problem. They may include:

• Ongoing diarrhoea, or pale, greasy, foul-smelling stools that are hard to flush
• Bloating, wind and tummy cramps
• Unplanned weight loss, even when eating normally
• Tiredness and weakness
• Poor growth in children

Over time, nutrient deficiencies can cause further signs:

What causes malabsorption?

There are many possible causes. Some of the most common include:

Conditions that damage the gut lining

• Coeliac disease: an autoimmune reaction to gluten that damages the small intestine.
• Crohn’s disease: inflammation that can affect the small bowel’s ability to absorb nutrients.
• Infections: such as giardia, which can cause lasting symptoms if not treated.

Problems with digestion

• Pancreatic insufficiency: when the pancreas does not make enough digestive enzymes, for example in chronic pancreatitis or cystic fibrosis.
• Lactose intolerance: low levels of the enzyme lactase, making milk sugar hard to digest.
• Liver and gallbladder problems: reduced bile makes it harder to absorb fat and fat-soluble vitamins.

Other causes

• Small intestinal bacterial overgrowth (SIBO)
• Surgery that removes or bypasses part of the bowel, including some types of weight-loss surgery
• Some medicines that affect absorption over time

How is malabsorption diagnosed?

Your doctor will ask about your symptoms, diet and medical history. Tests may include blood tests to check for anaemia, vitamin and mineral levels and coeliac antibodies; stool tests to look for fat, infection or pancreatic enzyme levels; breath tests for lactose intolerance or SIBO; and sometimes an endoscopy or scan.

If you suspect coeliac disease, keep eating gluten until you have been tested. Cutting it out beforehand can make the results inaccurate.

How is malabsorption syndrome treated?

Treatment focuses on the underlying cause, replacing missing nutrients and supporting your diet.

• Treating the cause: for example, a strict gluten-free diet for coeliac disease, medicines for Crohn’s disease, or antibiotics for an infection or SIBO.
• Enzyme replacement: people with pancreatic insufficiency may be prescribed enzyme capsules to take with meals.
• Replacing nutrients: your doctor may prescribe iron, vitamin B12, vitamin D, calcium or other supplements based on your blood results. Some may need to be given by injection.
• Diet changes: adjusting the type of fat, fibre or lactose you eat to reduce symptoms.

Always take supplements under medical guidance. Some, such as vitamin K, can interact with medicines like warfarin.

Eating well with malabsorption

A nutrition professional can tailor your diet to your diagnosis. Some general tips that often help:

• Eat smaller meals more often to make digestion easier.
• Choose nutrient-dense foods, such as eggs, fish, chicken, yoghurt, lentils and well-cooked vegetables.
• If you are lactose intolerant, try lactose-free milk or yoghurt and laban, which many people tolerate better.
• If fatty foods trigger symptoms, choose grilled or baked dishes and use less ghee and oil, unless advised otherwise.
• Drink plenty of fluids, especially if you have diarrhoea or live in a hot climate.
• Keep a food and symptom diary to spot patterns.

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When to see a doctor or nutrition professional

• Diarrhoea lasting more than two to three weeks
• Pale, greasy or very foul-smelling stools
• Unexplained weight loss or poor growth in a child
• Ongoing tiredness, anaemia or easy bruising
• Blood in your stools, fever or severe tummy pain, which need prompt medical attention

Frequently asked questions

Can malabsorption be cured?

It depends on the cause. Some causes, like infections, can be cured. Others, like coeliac disease or pancreatic insufficiency, are long-term but can be well managed with diet, enzymes or medicines.

What foods should I avoid with malabsorption?

This depends on your diagnosis. People with coeliac disease must avoid gluten, while those with lactose intolerance may need to limit lactose. Avoid cutting out foods without advice, as it can worsen deficiencies.

Can malabsorption cause weight loss even if I eat a lot?

Yes. If your body cannot absorb the energy and nutrients from food, you may lose weight even with a good appetite. This should always be checked by a doctor.

Which vitamins are most affected by malabsorption?

The fat-soluble vitamins A, D, E and K are commonly affected, along with iron, folate and vitamin B12. Blood tests can show which ones you need to replace.

Get personalised nutrition support

Dr. Rida Saeed works with people living with digestive conditions to build balanced, practical eating plans. Find out more about her gut health nutrition service, or read about coeliac disease and nutritional deficiencies. Consultations are online, so you can join from the UAE, Pakistan or anywhere. Book via WhatsApp +971 54 448 6145.

This article is for general information only and is not a substitute for medical advice. Please speak to your doctor or a qualified health professional about your individual needs.