Malabsorption involves many disorders in which there is an inability of the gut to absorb nutrients from dietary intake, potentially including water and/or electrolytes Electrolytes Electrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions. Electrolytes. A closely related term, maldigestion is the inability to break down large molecules of food into their smaller constituents. Malabsorption and maldigestion can affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment macronutrients ( fats Fats The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (dietary fats) as a source of energy. Energy Homeostasis, proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis, and carbohydrates Carbohydrates A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of cn(H2O)n. The largest class of organic compounds, including starch; glycogen; cellulose; polysaccharides; and simple monosaccharides. Basics of Carbohydrates), micronutrients (vitamins and minerals Minerals Electrolytes), or both. These disorders present with weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, weakness, and fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia. There are many causes, and the goal of management is to reduce symptoms, with specific treatments aimed at the underlying cause.
Last updated: 27 Jun, 2022
Maldigestion refers to the inability to break down large molecules of food in the intestinal lumen into their smaller components.
Malabsorption refers to the inability to transport nutrients across the intestinal mucosa into blood circulation. The term “malabsorption,” however, is often used to refer to both of these processes since food that is not digested properly will not be absorbed properly either.
Global malabsorption:
Selective malabsorption:
Malabsorption has many causes from various mechanisms.
Type of nutrient | Normal process | Abnormal process |
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Fats Fats The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (dietary fats) as a source of energy. Energy Homeostasis |
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Proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis |
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Carbohydrates Carbohydrates A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of cn(H2O)n. The largest class of organic compounds, including starch; glycogen; cellulose; polysaccharides; and simple monosaccharides. Basics of Carbohydrates |
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Malabsorption should be suspected in a patient with chronic diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, unexplained weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, and/or unexplained nutrient deficiencies.
Characteristic skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions rash Rash Rocky Mountain Spotted Fever associated with pellagra Pellagra A disease due to deficiency of niacin, a b-complex vitamin, or its precursor tryptophan. It is characterized by scaly dermatitis which is often associated with diarrhea and dementia (the three d’s). Water-soluble Vitamins and their Deficiencies
Image: “This child has the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions rash Rash Rocky Mountain Spotted Fever associated with pellagra Pellagra A disease due to deficiency of niacin, a b-complex vitamin, or its precursor tryptophan. It is characterized by scaly dermatitis which is often associated with diarrhea and dementia (the three d’s). Water-soluble Vitamins and their Deficiencies” by CDC. License: Public DomainWork-up should first determine whether the malabsorption is global or selective, and then attempt to determine the underlying etiology. This is achieved through a history and physical examination, laboratory testing, and, in some cases, imaging and endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD).
The etiology can often be ascertained from the history.
Detailed history for symptoms as above, as well as:
Physical examination for:
Lab tests and imaging should be ordered based on suspected diagnosis, and may include: