What does the general physician need to know about Malabsorption ?

Malabsorption syndrome 

Malabsorption is a broad term used to describe the inability to absorb nutrients through the gut lining into the bloodstream. This means the failure of the GI tract, usually the small intestine, to absorb one or more substances from the diet. This is generally the result of some defect or damage to the mucosal lining of the small intestine where most of our nutrient absorption takes place. 

  • Malabsorption is not a disease by itself, but rather the result of some other condition that is present. 
  • Malabsorption may affect one or more of the many nutrients present in the diet, including protein, fat, carbohydrate, vitamins, and minerals. 

  • Celiac disease (sprue, gluten - sensitive enteropathy) 
  • Crohn's disease 
  • The degree of malabsorption depends on the type of underlying condition and the extent to which it has affected the gut. Some of the more common malabsorption syndromes are due to bacterial or parasitic infections, 

  • Tropical sprue
  •  Liver disease (including cirrhosis, hepatitis, and gallstones),
  • Whipples disease 
  • Lactase deficiency 
  • Parasitic diseases 
  • Other causes of malabsorption can be due to past intestinal surgeries, bacterial overgrowth, AIDS, radiation to the abdomen, diabetes, lymphoma or motility disorders 
The most common symptoms of malabsorption include:
  • Diarrhea, steatorrhea (excessive amount of fat in the stool), and abdominal distention with cramps, bloating, and gas due to impaired water and carbohydrate absorption, and irritation from unabsorbed fatty acids. The individual may also report explosive diarrhea with greasy, foul-smelling stools. 

  • Anemia, with weakness and fatigue due to inadequate absorption of vitamin B12, iron, and folic acid 

  • Edema (fluid retention in the body's tissues) due to decreased protein absorption 
  • Malnutrition and weight loss due to decreased fat, carbohydrate, and protein absorption. Weight may be 80-90% of usual weight despite increased oral intake of nutrients. 
  • Muscle cramping due to decreased vitamin D, calcium, and potassium levels 
  • Muscle wasting and atrophy due to decreased protein absorption and metabolism 
  • Perianal skin burning, itching, or soreness due to frequent loose stools.

Risk factors for malabsorption syndrome include
  • premature birth 
  • family history of malabsorption or cystic fibrosis 
  • use of certain drugs, such as mineral oil or other laxatives 
  • travel to foreign countries 
  • intestinal surgery, including bowel transplantation 
  • excess alcohol consumption.
Celiac disease (sprue, gluten - sensitive enteropathy) is a condition where the mucosal lining of the small intestine is damaged by ingestion of gluten. Gluten is a protein found in wheat, rye, barley and oats but not in corn or rice. The mechanisms and reason for this reaction are unknown, but it is thought to be genetic in nature and likely an autoimmune condition and is not considered an allergy. 

Maintaining a gluten-free diet restores the damaged mucosal lining to normal and allows one to absorb normally leading to a normal life. On occasion, patients may fail to respond to a gluten-free diet and could have refractory sprue or intestinal lymphoma.

Tropical sprue 
  • is a malabsorptive disorder more often in people from the Caribbean, India, or southeast Asia and should be suspected in anyone presenting with malabsorption that has visited the tropics.
  •  Although its cause is unknown, it is thought to be related to environmental factors, including infection, intestinal parasites, or possibly the consumption of certain food toxins.
  •  Symptoms often include a sore tongue, anemia, weight loss, along with diarrhea and passage of fatty stools. Treatment consists of antibiotics, often Tetracycline, for up to 6 months. 

Whipples disease 
  • is a systemic bacterial illness, Tropheryma whipplei,  usually affecting middle age. 
  • The cause is thought to be related to bacterial infection, resulting in nutritional deficiencies, chronic low-grade fever, diarrhea, joint pain, weight loss, and darkening of the skin's pigmentation. 
  • Other organs of the body may be affected, including the brain, heart, lungs, and eyes. 
  • It is diagnosed by taking a small bowel biopsy through an endoscope, and the treatment is antibiotics for one year or longer 

Lactase deficiency 
  • can result in malabsorption and occurs in 15 percent of Caucasian, 50 percent of blacks and nearly 90 percent of Asians
  • Often times, however, one can have a partial lactase deficiency that causes symptoms but not full-blown malabsorption. Treatment is to avoid lactose-containing dairy products (milk, ice cream ) 

Short bowel syndromes 
  • may be present at birth (congenital) or the result of surgery-reduce the surface area of the bowel available to absorb nutrients and can also result in malabsorption syndrome. 
  • Congenital short bowel syndrome occurs in about 24 out of 100,000 live births and has a high mortality rate (about 38%).

Diagnosis of malabsorption
  • The diagnosis of malabsorption syndrome and identification of the underlying cause can require extensive diagnostic testing. 
  • First phase - a thorough medical history and physical examination by a physician, who will then determine the appropriate laboratory studies and radiological studies to assist in diagnosis.
  • A 72-hour stool collection may be ordered for fecal fat measurement; increased fecal fat in the stool collected indicates malabsorption. 
  • A biopsy of the small intestine
  •  Ultrasound, computed tomography scan (CT scan), magnetic resonance imaging (MRI), barium enema, or other x rays to identify abnormalities of the gastrointestinal tract and pancreas may also be ordered.
Investigations for malabsorption and its causes

Routine – 

  • stool microscopy and its culture
  • Fe, folate, Vit. B12
  • Ca, albumin, alk. Phosphatase, Mg,
  • Celiac antibodies 


  • H2 breath testing – sugar
  • Fecal elastase
  • Duodenal biopsy
  • Barium studies
  • D-xylose  test
  • Schilling test
  • SeHCAT test

  • Fluid and nutrient monitoring and replacement is essential for any individual with malabsorption syndrome. 
  • Hospitalization may be required when severe fluid and electrolyte imbalances occur. 
  • Consultation with a dietitian to assist with nutritional support and meal planning is helpful. If the patient is able to eat, the diet and supplements should provide bulk and be rich in carbohydrates, proteins, fats, minerals, and vitamins. The patient should be encouraged to eat several small, frequent meals throughout the day, avoiding fluids and foods that promote diarrhea. 
  • Intake and output should be monitored, along with the number, color, and consistency of stools.
  • The individual with malabsorption syndrome must be monitored for dehydration, including dry tongue, mouth and skin; increased thirst; low, concentrated urine output; or feeling weak or dizzy when standing.
  •  Pulse and blood pressure should be monitored, observing for increased or irregular pulse rate, or hypotension (low blood pressure). 
  • The individual should also be alert for signs of nutrient, vitamin, and mineral depletion, including nausea or vomiting; fissures at corner of mouth; fatigue or weakness; dry, pluckable hair; easy bruising; tingling in fingers or toes; and numbness or burning sensation in legs or feet.
  •  Fluid volume excess, as a result of diminished protein stores, may require fluid intake restrictions. The physician should also be notified of any shortness of breath. 
Specific medical management  dependents upon the cause.
  • Tropical sprue consists of folic acid supplements and long-term antibiotics
  • Whipple's disease also may require long-term use of antibiotics, such as tetracycline.
  • Injections of vitamin B12 in terminal ileal disease.
  • Enzymes to replace missing intestinal enzymes, or antispasmodics to reduce abdominal cramping and associated diarrhea
  • The expected course for the individual with malabsorption syndrome varies depending on the cause. 
  • The onset of symptoms may be slow and difficult to diagnose. 
  • Treatment may be long, complicated, and changed often for optimal effectiveness. 
  • Patience and a positive attitude are important in controlling or curing the disorder. 
  • Careful monitoring is necessary to prevent additional illnesses caused by nutritional deficiencies.