Malabsorption Syndrome

Overview

Malabsorption syndrome is a group of conditions where the small intestine is unable to absorb enough nutrients into the bloodstream from the food that one eats. The nutrients that the small intestine has a problem absorbing are macronutrients like proteins, carbohydrates, and fats, or micronutrients like vitamins and minerals or both. Malabsorption can be total, where absorption of all nutrients is impaired, or partial, where only specific nutrients are not absorbed. It causes excessive defecation, nutritional deficiency, and gastrointestinal symptoms.

What Is the Pathophysiology?

Digestion involves mechanical processes and enzymatic hydrolysis to break down the food. The mechanical process includes chewing, churning, and to and fro mixing of the food in the stomach and small intestine. Enzymatic hydrolysis is achieved by gastric, pancreatic, and biliary secretions. The final products of digestion are then absorbed by the epithelial cells of the small intestine. Any alteration or pathological interference in the above stages causes malabsorption, as it disturbs the typical sequence of digestion, absorption, and transport of nutrients.

What Are the Disorders of Malabsorption?

• Fat Malabsorption:

Fat malabsorption is the most common cause of malabsorption. Fat which are not absorbed in the small intestine moves through the colon resulting in fatty stools called steatorrhea. These fatty stools are greasy, runny, and very smelly. They appear to be light-colored and float. This malabsorption can result in the malabsorption of fat-soluble vitamins such as A, D, E, and K.

• Carbohydrate Malabsorption:

Some people can be sensitive to one or more carbohydrates. This can be felt as gas or bloating initially. Those carbohydrates that do not get absorbed completely in the intestine get fermented in the colon by the bacteria. The bacteria break these carbohydrates into gases and small chains of fatty acids. The gases result in intestinal gas and the chains of fatty acids into fatty acid stools.

• Bile Acid Malabsorption:

Fat malabsorption can sometimes be caused due to reduced bile. In some other conditions, it is caused by leftover bile acids in the small intestine and moving these to the colon. This is called bile acid malabsorption.

• Protein Malabsorption:

Protein malabsorption occurs only if the person has an intolerance.

What Are the Causes Causes?

The main cause is some defect or damage to the mucosal lining of the small intestine. It can broadly be classified into premucosal, mucosal, and postmucosal malabsorption.

1. Premucosal: Caused due to diseases and conditions that cause impaired digestion by affecting the secretion of digestive enzymes. Digestion is impaired in conditions like pancreatitis, pancreatic cancer, and cystic fibrosis. They affect the pancreatic enzyme secretion. Cholestatic liver disease, biliary atresia, and bacterial overgrowth reduce the bile salt concentration in the intestines.

2. Mucosal: It is due to the conditions that affect the intestinal mucosa and reduce the absorptive area. For example, celiac disease, inflammatory bowel disease, short bowel syndrome (SBS), and Whipple’s disease.

3. Postmucosal: Impaired absorption due to conditions that result in impaired nutrient transport in the body by vascular and lymphatic obstruction. For example intestinal lymphangiectasia, macroglobulinemia, etc.

The small intestine can also get damaged by the following:

• Infections caused by bacteria, viruses, parasites, inflammation, trauma, or surgery.

• Prolonged use of antibiotics.

• Lactose intolerance.

• Radiation therapy.

• Use of certain drugs like Tetracycline, Cholestyramine, Colchicine, etc.

• Gallbladder diseases.

Once the lining gets damaged, the nutrients are not absorbed and they pass through their stool.

What Are the Symptoms?

The symptoms depend on the nutrients that is not being absorbed into the body. The other symptoms are as a result of that specific nutrient deficiency. The general symptoms are

• Persistent diarrhea.

• Foul-smelling stool.

• Light-colored or bulky stool (Steatorrhea).

• Floating stools.

• Weight loss.

• Scaly skin.

• Dry hair, hair fall, and edema due to protein deficiency.

• Anemia due to vitamin B12, folic acid, and iron deficiency.

• Malnutrition, weight loss, low blood pressure, and muscle wasting.

• Some females might stop menstruating.

• Growth retardation and delayed puberty in children.

What Are the Risk Factors?

The risk factors include

• Stomach flu in children.

• Cancer patients.

• People who have celiac disease, cystic fibrosis, and Crohn’s disease.

• People who use antibiotics and laxatives frequently.

• After gastric surgeries like bariatric surgery.

• Parasitic intestinal infection.

• Consuming a lot of alcohol.

What Is the Diagnosis?

If a person is suffering from persistent diarrhea or deficiency even after consuming a healthy diet, the doctor will perform specific tests to diagnose their condition. They will also look for diseases that might cause impaired absorption. These tests include:

• Stool Tests: Stool or feces samples are tested for fat. The presence of too much fat is a sign of malabsorption.

• Blood Tests: The levels of nutrients like vitamin B12, vitamin D, iron, calcium, albumin, protein, and phosphorus are measured in the blood. Low levels of one or many of these nutrients might indicate impaired absorption or reduced intake.

• Sweat Test: A sweat sample is tested in the diagnosis of cystic fibrosis. Cystic fibrosis causes a lack of enzymes to digest food.

• Breath Test: Breath test is used to diagnose lactose intolerance. The unabsorbed lactose gets broken down by the bacteria in the colon to form hydrogen gas. This hydrogen gas gets into the bloodstream and enters the lungs, from where it gets exhaled. The breath of the patient gets tested for this hydrogen gas.

• Biopsy: A small tissue sample is collected from the inside of the small intestine. This tissue is then studied for signs of infection or other problems. The biopsy is usually collected during endoscopy.

• CT Scan: CT scan can be used to see the structural changes in the small intestine. For example, a thickened intestinal wall can be a sign of Crohn’s disease.

What Is the Treatment?

The treatment depends on the cause.

• The person will be given nutrients and fluids that the body is not able to absorb. The doctor will treat the health condition that is causing this impaired absorption.

• A dietician will create a diet plan for the individual, which will include nutrients that can be easily absorbed by the body, and other supplements to treat nutritional deficiency. They might give them enzyme and vitamin supplements.

• If the cause is increased peristaltic movement of the digestive tract, then medicines are prescribed to relax it. This makes the passing food stay in the intestine longer, thus giving it more time to get absorbed into the bloodstream.

• Any infection of the digestive tract can be treated by antibiotics.

Conclusion

If a child has any signs or symptoms of malabsorption, like diarrhea for a long time, it is best to consult the physician and get tested right away. Lack of essential nutrients will prevent the healthy growth and development of the child. The earlier one recognizes the signs and gets treated, the less will be permanent damage to the body.