poorabsorption

Poor absorption, commonly referred to as malabsorption, is a reduced ability to absorb nutrients from the gastrointestinal tract. It can involve macronutrients (carbohydrates, proteins, fats) and micronutrients (vitamins and minerals). Most absorption occurs in the small intestine, particularly the jejunum and ileum; damage to the mucosa, reduced absorptive surface, enzyme deficiencies, or altered intestinal transit can impair uptake.

Causes are diverse and often grouped by the underlying defect. Mucosal diseases such as celiac disease, Crohn’s disease, tropical sprue, and other inflammatory or infectious conditions can damage the intestinal lining. Pancreatic or biliary causes include chronic pancreatitis and pancreatic insufficiency or bile acid malabsorption. Infections and dysbiosis, notably Giardia infection or small intestinal bacterial overgrowth, can disrupt absorption. Post-surgical states with extensive small bowel resection or bypass reduce absorptive area. Medications such as orlistat, certain bile acid sequestrants, or prolonged antibiotic use may interfere with absorption. Other factors include radiation enteritis, renal or liver disease, and certain systemic illnesses.

Symptoms often include chronic diarrhea, steatorrhea, weight loss, abdominal bloating and pain, weakness, and signs of nutrient deficiencies such as anemia or bone disorders.

Diagnosis relies on clinical suspicion supported by tests such as quantitative stool fat measurement, fecal elastase for pancreatic insufficiency, D-xylose testing, celiac serology, endoscopy with biopsy, and nutrient panels. Imaging and specialized tests may be used to identify structural or functional abnormalities.

Management focuses on treating the underlying cause, dietary modifications, and nutritional supplementation. Pancreatic enzyme replacement therapy is used for pancreatic insufficiency; a gluten-free diet is essential for celiac disease; antibiotics may treat SIBO. Fat-soluble vitamins and other deficient nutrients are corrected as needed. Prognosis varies with the cause and response to therapy.