Malabsorption

Question 1

What is malabsorption?

Answer 1

Malabsorption occurs when an individual cannot absorb macro and micronutrients from their diet.

Question 2

What can malabsorption be specific to?

Answer 2

Malabsorption may be specific to a macro or micronutrient, such as fat or Vitamin B12.

Question 3

Can malabsorption be more generalised?

Answer 3

Malabsorption can also be more generalised, affecting the absorption of multiple nutrients.

Question 4

What are some causes of malabsorption?

Answer 4

Some causes of malabsorption include alterations to secretions, alterations in structure/absorptive capacity, alterations in motility, and reduction in blood flow.

Question 5

How can alterations to secretions lead to malabsorption?

Answer 5

Changes in secretions, such as insufficient digestive enzymes or bile, can impair the breakdown and absorption of nutrients.

Question 6

How does alteration in structure/absorptive capacity contribute to malabsorption?

Answer 6

Conditions like intestinal inflammation, damage to the intestinal lining, or surgical removal of a portion of the intestine can reduce the surface area available for nutrient absorption.

Question 7

How does alteration in motility affect nutrient absorption?

Answer 7

Abnormalities in gut motility, such as slowed or accelerated transit time, can impact the contact between nutrients and the porous surface, leading to malabsorption.

Question 8

What role does reduced blood flow play in malabsorption?

Answer 8

Insufficient blood flow to the gastrointestinal tract can limit the delivery of nutrients to the absorptive cells, resulting in malabsorption.

Question 9

What are some standard diagnostic features of malabsorption?

Answer 9

Some standard diagnostic features of malabsorption include diarrhoea or changes in stool consistency or colour, abdominal distension, flatulence or excessive gas, loss of weight in adults or growth failure in children, hypoproteinaemia (low serum albumin/prealbumin), iron deficiency anaemia, and low serum ferritin.

Question 10

What are some longer-term signs of malabsorption?

Answer 10

Longer-term signs of malabsorption may include osteoporosis, deficiency of vitamin B12 and folate.

Question 11

What are the presenting features of fat malabsorption?

Answer 11

The presenting feature of fat malabsorption is steatorrhea, which refers to pale, malodorous, greasy, and unformed stools. These stools are often challenging to flush and may leave a greasy residue in the toilet.

Question 12

What are the presenting features of carbohydrate malabsorption?

Answer 12

Carbohydrate malabsorption typically presents as watery and frothy diarrhoea. This is caused by the presence of fermented sugars in the stool.

Question 13

What are the principles of dietary treatment for malabsorption?

Answer 13

The principles of dietary treatment for malabsorption include replacing large fluid and electrolyte losses, treating the primary disorder if appropriate, providing symptom relief, and restoring optimal nutritional status with supplementation for micronutrients and trace elements as needed.

Question 14

Can increasing the amount taken orally always lead to increased absorption in malabsorption?

Answer 14

No, increasing the amount taken orally may not necessarily lead to increased absorption in cases of malabsorption.

Question 15

How is Vitamin B12 absorption affected by malabsorption?

Answer 15

Vitamin B12 is absorbed in the terminal ileum. If the terminal ileum is removed or dysfunctional, no B12 will be absorbed, and therefore injections of B12 are needed.

Question 16

What are the common nutritional deficiencies resulting from malabsorption in the UK?

Answer 16

Generalized nutrient deficiencies are likely in malabsorption cases. The risk of specific defects is increased by disease or resection in particular sites of the GI tract, chronic diarrhoea, and self-imposed dietary restriction.

Question 17

Which population groups are especially at risk of dehydration due to malabsorption-related diarrhoea?

Answer 17

Older people, infants, and young children are especially at risk of dehydration due to the loss of fluid and electrolytes during acute episodes of diarrhoea.

Question 18

What nutritional deficiencies are commonly seen in alcoholic liver disease?

Answer 18

Alcoholic liver disease can lead to thiamine (B1) and Vitamin D deficiencies.

Question 19

What nutritional deficiencies are commonly seen in inflammatory bowel disease?

Answer 19

Inflammatory bowel disease can lead to deficiencies in iron, vitamin B12, vitamin D, vitamin K, folic acid, selenium, zinc, vitamin B6, and vitamin B1.

Question 20

What gastric function disturbances can occur after gastric resection?

Answer 20

Gastric resection can lead to rapid emptying of the stomach remnant or increased intestinal motility, reduced secretion of intrinsic factor (implicated in B12 deficiency), abolition of the normal pH gradient in the small intestine, rapid absorption of glucose leading to dumping syndrome, reduced absorption of certain foods (especially protein and fat), inadequate mixing of enzymes and bile, and reduced secretion of pancreatic enzymes.

Question 21

What is the consequence of markedly accelerated gastric emptying after gastric resection?

Answer 21

Markedly accelerated gastric emptying can lead to dumping syndrome, which involves the malabsorption of fluids and nutrients, resulting in diarrhoea.

Question 22

What two types of dumping syndrome can occur after gastric resection?

Answer 22

Dumping syndrome can manifest as early or late dumping after gastric resection.

Question 23

What are the symptoms and causes of early dumping syndrome?

Answer 23

Early dumping syndrome occurs soon after eating and is characterised by sweating, dizziness, faintness, rapid, weak pulse, and hypotension. It is caused by the rapid and early delivery of a hyperosmolar load into the jejunum.

Question 24

What are the symptoms and causes of late dumping syndrome?

Answer 24

Late dumping syndrome typically occurs approximately 2 hours after a meal and presents with symptoms like weakness, coldness, faintness, and sweating. It is caused by the overproduction of insulin in response to the rapid absorption of glucose.

Question 25

What are some alterations to secretions that can occur in malabsorption?

Answer 25

Alterations to secretions can include enzyme deficiencies and disaccharidase deficiency, such as primary alactasia or secondary lactase deficiency.

Question 26

What are some intraluminal factors that can affect malabsorption?

Answer 26

Intraluminal factors can include high pH in the duodenum, such as in achlorhydria (absence of stomach acid), or low pH in the duodenum, as seen in conditions like Zollinger-Ellison syndrome.

Question 27

What is lactose malabsorption?

Answer 27

Lactose malabsorption refers to the inability to properly digest lactose, a disaccharide found in milk and dairy products, due to insufficient lactase enzyme activity.

Question 28

What happens when lactose is not digested correctly?

Answer 28

When lactose is not digested correctly, it remains in the intestine, causing osmotic diarrhoea. The lactose is further fermented by colonic bacteria, leading to symptoms such as abdominal distension, flatulence, and explosive watery diarrhoea.

Question 29

What are the three main forms of lactose intolerance?

Answer 29

The three main forms of lactose intolerance are primary lactase deficiency (age-related decline in lactase production), secondary lactase deficiency (caused by intestinal diseases or injuries), and congenital lactase deficiency (rare genetic disorder resulting in the complete absence of lactase).

Question 30

What is congenital alactasia?

Answer 30

Congenital alactasia is a rare autosomal recessive disorder characterised by the absence of lactase enzyme. Individuals with this condition require a lifelong lactose-free diet.

Question 31

What is primary lactase deficiency?

Answer 31

Primary lactase deficiency is characterised by a gradual reduction in lactase production, typically occurring in older children and adults. It results in symptoms of lactose maldigestion, such as abdominal discomfort and diarrhoea, after consuming lactose-containing foods.

Question 32

What is secondary lactase deficiency?

Answer 32

Secondary lactase deficiency is a common and usually temporary condition that occurs due to damage to the intestinal brush border. It is characterised by persisting diarrhoea even after treating the primary disorder causing the damage.

Question 33

How can surgery affect the structure and absorptive capacity of the gastrointestinal tract?

Answer 33

Surgical procedures such as intestinal resection, short bowel syndrome, gastrocolic fistula, jejunoileal bypass, and specific bariatric surgery procedures can alter the structure and absorptive capacity of the gastrointestinal tract.

Question 34

What are some examples of inflammatory conditions that can lead to structure and absorptive capacity alterations?

Answer 34

Inflammatory bowel disease, pancreatitis, and other inflammatory conditions can cause alterations in the structure and absorptive capacity of the gastrointestinal tract.

Question 35

What is villous atrophy, and what condition is it commonly associated with?

Answer 35

Villous atrophy refers to the flattening of the intestinal villi, which reduces the absorptive surface area. It is commonly seen in coeliac disease.

Question 36

How can deconjugation of bile salts impact absorption?

Answer 36

Deconjugation of bile salts due to bacterial colonization in the small intestine, as seen in blind loop syndrome, can affect absorption.

Question 37

What factors can lead to mucosal damage in the gastrointestinal tract?

Answer 37

Mucosal damage can be caused by certain drugs, irradiation therapy, and other factors.

Question 38

How can infections and obstruction affect the structure and absorptive capacity of the gastrointestinal tract?

Answer 38

Infections such as giardia or Whipple’s disease, as well as obstruction caused by conditions like lymphatic obstruction, lymphoma, or pancreatic carcinoma, can lead to alterations in the structure and absorptive capacity of the gastrointestinal tract.

Question 39

What is coeliac disease?

Answer 39

Coeliac disease is an inflammatory condition of the small intestinal mucosa induced by ingesting gluten, a protein found in wheat, rye, barley, and oats.

Question 40

What are the common symptoms and consequences of coeliac disease?

Answer 40

Coeliac disease can lead to malabsorption, weight loss, and malnutrition. While not all patients lose weight, they may experience poor absorption of iron and calcium, resulting in anaemia and osteoporosis.

Question 41

How can coeliac disease be managed?

Answer 41

Coeliac disease improves when gluten is excluded from the diet. Following a strict gluten-free diet is the primary treatment for managing coeliac disease.

Question 42

Which grains contain gluten?

Answer 42

Gluten is found in wheat, rye, barley, and oats. However, it’s important to note that oats can be tolerated by some individuals with coeliac disease if they are specifically labeled as gluten-free.

Question 43

Are there gluten-free products available in the market?

Answer 43

Many gluten-free products are available in the market to cater to individuals with coeliac disease or gluten intolerance.

Question 44

What are the main inflammatory bowel disease (IBD) types?

Answer 44

The main types of IBD are Crohn’s disease and ulcerative colitis.

Question 45

How is Crohn’s disease and ulcerative colitis characterized?

Answer 45

Crohn’s disease and ulcerative colitis are progressive diseases characterized by mucosal inflammation and follow a relapsing and remitting disease course.

Question 46

What are some common clinical features of IBD?

Answer 46

Common clinical features of IBD include abdominal pain, diarrhoea (sometimes with blood and mucus), urgency and tenesmus (feeling the need to have a bowel movement even when the rectum is empty), weight loss, and fatigue.

Question 47

What is the role of surgery in the treatment of IBD?

Answer 47

Surgery is often a part of the treatment approach for IBD, especially in severe complications or insufficient medical management.

Question 48

What deficiencies are common in IBD, and why is routine multivitamin supplementation recommended?

Answer 48

Vitamin and mineral deficiencies are common in IBD, including deficiencies in iron, zinc, copper, beta-carotene, folate, vitamins B12, B6, E, C, and D. Routine multivitamin supplementation is recommended to address these deficiencies and support optimal nutrition.

Question 49

What are the potential consequences of prolonged, bloody, or severe diarrhea in IBD?

Answer 49

Prolonged, bloody, or severe diarrhoea in IBD can lead to poor absorption of nutrients, including potassium, sodium, zinc, magnesium, and iron. This can result in complications such as anaemia, dehydration, severe weight loss, and nutritional depletion.

Question 50

How can ileal resection or small intestinal bacterial overgrowth in Crohn’s disease contribute to deficiencies?

Answer 50

Ileal resection or small intestinal bacterial overgrowth in Crohn’s disease can lead to deficiencies in nutrients such as vitamin B12 and lactase, resulting in malabsorption and related symptoms.

Question 51

Why is osteoporosis common in IBD?

Answer 51

Osteoporosis is common in IBD and is likely due to a combination of factors, including inflammatory activity leading to poor nutrient intake, malabsorption, and the use of certain medications. These factors can contribute to bone loss and increased risk of fractures.

Question 52

What is the primary cause of anaemia in IBD?

Answer 52

Iron deficiency is the primary cause of anaemia in IBD. It can result from dietary restrictions, intestinal bleeding, and malabsorption due to inflammation or ulceration in the gastrointestinal tract.

Question 53

What is intestinal failure (IF)?

Answer 53

Intestinal failure refers to a reduction in the gut function below the minimum necessary to absorb macronutrients and/or water and electrolytes. It requires intravenous supplementation to maintain health and/or growth.

Question 54

How can intestinal resection affect nutrient absorption?

Answer 54

Intestinal resection, particularly of the small bowel, can significantly impact nutrient absorption. The outcome for the patient depends on factors such as the type, length, and quality of the remaining small bowel, as well as the presence or absence of a functioning colon.

Question 55

What are the potential outcomes of extensive small bowel resection?

Answer 55

Extensive small bowel resection may result in the remaining end of the small intestine being anastomosed to the colon or ending in a stoma on the abdomen. These surgical interventions aim to maintain or restore digestive and absorptive function.

Question 56

How does the loss of the ileum and jejunum affect digestion and absorption?

Answer 56

The loss of the ileum and some of the jejunum significantly impairs digestive and absorptive function. These parts of the small intestine are crucial for nutrient absorption, especially vitamin B12 and bile acid reabsorption.

Question 57

What is considered a short bowel in terms of residual small bowel length?

Answer 57

A residual small bowel length of less than 200cm is typically deemed as short bowel, indicating a significant reduction in the functional surface area available for nutrient absorption.

Question 58

How can impaired transport mechanisms affect nutrient absorption?

Answer 58

Impaired transport mechanisms can impact nutrient absorption. For example, congenital lymphangiectasia can impair fat transport, while hereditary primary glucose and galactose malabsorption can affect monosaccharide transport.

Question 59

What are some conditions that can lead to impaired fat transport?

Answer 59

One example of impaired fat transport is congenital lymphangiectasia, a condition characterised by dilated lymphatic vessels that improperly absorb fats from the intestine.

Question 60

What is the primary congenital malabsorption of glucose and galactose?

Answer 60

Congenital primary malabsorption of glucose and galactose is a rare genetic disorder affecting monosaccharides’ transport, specifically glucose and galactose, across the intestinal lining.

Question 61

How can vascular diseases impact nutrient absorption?

Answer 61

Vascular diseases, such as constructive pericarditis, right-sided heart failure, and mesenteric arterial or venous insufficiency, can reduce blood flow to the intestines. This reduction in blood flow can impair nutrient absorption.

Question 62

Is dietary restriction of protein indicated when malabsorption is due to enzyme deficiency?

Answer 62

No, dietary protein restriction is not indicated when malabsorption is due to a deficiency of enzymes involved in protein digestion. Restricting protein intake would not address the underlying enzyme deficiency and could lead to inadequate protein consumption.

Question 63

What should be done when increased protein losses occur due to malabsorption?

Answer 63

A high protein intake is indicated when increased protein losses occur due to malabsorption. This is necessary to compensate for the decreased absorption efficiency and ensure adequate protein intake for the body’s needs.

Question 64

What are the main functions of the pancreas in digestion?

Answer 64

The pancreas has three main functions essential for digestion: endocrine function (production of insulin and glucagon), exocrine function (release of digestive enzymes), and bicarbonate secretion to neutralise gastric acid.

Question 65

What are some examples of enzyme deficiencies related to the pancreas?

Answer 65

Lipase and proteolytic enzyme deficiencies are common examples of enzyme deficiencies related to the pancreas. Conditions such as pancreatic insufficiency or familial lipoprotein lipase deficiency can result in insufficient production or activity of these enzymes.

Question 66

What is cystic fibrosis?

Answer 66

Cystic fibrosis is an autosomal recessive disease that primarily affects the respiratory and gastrointestinal (GI) systems. It is characterised by the production of thick, sticky mucus that can block the pancreatic ducts and impair the secretion of pancreatic enzymes.

Question 67

How does cystic fibrosis affect the pancreas and nutrient absorption?

Answer 67

In cystic fibrosis, the plugging of the pancreatic ducts leads to obstruction and progressive damage to the pancreas. This prevents the secretion of pancreatic enzymes, resulting in malabsorption of nutrients, particularly proteins, fats, and fat-soluble vitamins.

Question 68

What are some nutritional considerations in cystic fibrosis?

Answer 68

Nutritional considerations in cystic fibrosis include poor energy intake, increased energy expenditure, and impaired nutrient absorption. Malabsorption can lead to deficiencies in protein, fats, and fat-soluble vitamins. Undigested fat may also bind to other minerals and increase their excretion.

Question 69

What are some specific vitamin deficiencies seen in cystic fibrosis?

Answer 69

Cystic fibrosis can lead to deficiencies in various vitamins, including:

Vitamin Deficiency can result in night blindness.
Vitamin D: While rare, deficiency can cause rickets or osteomalacia.
Vitamin K: Deficiency can prolong bleeding time.

Question 70

What are the nutritional consequences of pancreatic damage, regardless of the cause?

Answer 70

Regardless of the cause of pancreatic damage, the nutritional consequences are similar. They include endocrine insufficiency, which can lead to diabetes (Type 3c diabetes), and exocrine insufficiency, which results in malabsorption and various symptoms such as steatorrhea, abdominal bloating, flatulence, weight loss, and micronutrient deficiencies.

Question 71

What are the symptoms associated with exocrine insufficiency in pancreatic disease?

Answer 71

Exocrine insufficiency in pancreatic disease can cause symptoms such as steatorrhea (excessive fat in the stools), abdominal bloating, flatulence, weight loss, and deficiencies in micronutrients, including vitamins and minerals.

Question 72

How is exocrine insufficiency managed in pancreatic disease?

Answer 72

Pancreatic enzyme replacement therapy manages exocrine insufficiency in pancreatic disease. This helps to improve digestion and nutrient absorption.

Question 73

What are some micronutrient deficiencies commonly associated with pancreatic insufficiency?

Answer 73

Pancreatic insufficiency is associated with multiple micronutrient deficiencies. One of the most clinically significant deficiencies is vitamin D deficiency, which can lead to osteopenia and osteoporosis.

Question 74

What is fat malabsorption?

Answer 74

Fat malabsorption refers to the impaired absorption of dietary fats in the gastrointestinal tract, leading to the passage of fatty stools, known as steatorrhea.

Question 75

How does fat malabsorption affect nutritional status?

Answer 75

Fat malabsorption can compromise nutritional status due to the loss of energy and fat-soluble vitamins (such as vitamins A, D, E, and K) via the stool. Steatorrhea can result in deficiencies of these essential nutrients.

Question 76

How might patient selection of low-fat foods affect fat malabsorption?

Answer 76

Some individuals with fat malabsorption may choose to consume low-fat foods to alleviate symptoms. However, this can further compromise their nutritional status, reducing their intake of essential fats and fat-soluble vitamins.

Question 77

How is steatorrhea due to pancreatic insufficiency treated?

Answer 77

pancreatic enzyme replacement therapy can manage Steatorrhea caused by pancreatic insufficiency. These enzymes help to break down fats and improve fat absorption.

Question 78

When should pancreatic enzyme replacement therapy be initiated in patients with pancreatic pathology?

Answer 78

It is recommended to consider pancreatic enzyme replacement therapy early on in patients who are losing weight and exhibiting symptoms of steatorrhea when there is significant impairment (around 90%) of exocrine pancreatic function.

Question 79

How should the nutritional management of fat malabsorption be approached?

Answer 79

Increasing energy intake to compensate for energy loss through faecal fat excretion is important. Restricting fat intake alone is not the solution. Additionally, supplements of fat-soluble vitamins may be necessary to prevent deficiencies.

Question 80

What are bile salts?

Answer 80

Bile salts are substances synthesised in the liver from cholesterol and secreted into the small intestine. They aid in the digestion and absorption of dietary fats.

Question 81

What can cause bile salt deficiency?

Answer 81

Bile salt deficiency can occur in conditions such as cirrhosis (liver disease), cholestasis (impaired bile flow), bacterial overgrowth in the small intestine, impaired ileal reabsorption of bile salts, or use of bile salt-binding medications.

Question 82

How does bile salt deficiency contribute to malabsorption?

Answer 82

Bile salts play a crucial role in emulsifying and absorbing dietary fats. When there is a deficiency of bile salts, the digestion and absorption of fats can be impaired, leading to fat malabsorption and the associated symptoms.

Question 83

What are some conditions associated with bile salt malabsorption?

Answer 83

Bile salt malabsorption can occur in conditions such as Crohn’s disease, ileal resection, and diseases affecting the liver and biliary system. It can lead to fat malabsorption and steatorrhea.

Question 84

How is bile salt malabsorption managed?

Answer 84

Management of bile salt malabsorption may involve addressing the underlying condition causing the deficiency, such as treating a liver disease or reducing bacterial overgrowth. In some cases, bile acid sequestrants may be prescribed to bind to bile salts and reduce their loss in the stool.

Question 85

What happens to the absorptive capacity for fluids and electrolytes after colon removal?

Answer 85

Resection of the large intestine, specifically the colon, results in a significant loss of absorptive capacity for fluids and electrolytes, particularly sodium.

Question 86

How much fluid and electrolyte loss can occur initially after colon removal?

Answer 86

Initially, considerable amounts of electrolytes and fluids can be lost, ranging from 1200 to 2000 millilitres per day.

Question 87

Does the remaining ileum adapt over time after a colon resection?

Answer 87

Yes, after 6-8 weeks, the remaining ileum (the last part of the small intestine) starts to adapt, and the losses of fluids and electrolytes decrease. However, ongoing losses of approximately 400 to 600 millilitres per day can still exist.

Question 88

What is the effect of colon resection on nutrient absorption?

Answer 88

One significant effect of colon resection is the inability to absorb vitamin B12 and bile acids in approximately one-third of patients.

Question 89

How can the nutritional consequences of colon resection be managed?

Answer 89

Management of the nutritional consequences of colon resection may involve dietary adjustments, such as increasing fluid and electrolyte intake, monitoring nutrient levels, and potentially supplementing with vitamin B12 and bile acid replacement therapy if deficiencies are present.