Gastrointestinal disease 1 Flashcards
What organs/ tissues/ glands are involved in digestion?
Mouth –> Salivary glands –> Tongue –> Teeth
Oesophagus
Stomach
Liver
Gall bladder –> Common bile duct
Pancreas
Small intestine
Large intestine
Rectum
Anus
What is malabsorption?
A generic term used for any illness causing impaired digestion and/or absorption
May be nutrient specific, e.g. lactose, or may impair the absorption of all nutrients, e.g. IBD.
What are the clinical features of malabsorption?
- Diarrhoea
- Steatorrhea
- Abdominal distension and flatulence
- Weight loss and poor appetite
- Faltering growth in children
- Micronutrient deficiencies e.g. anaemia
What are some causes of malabsorption?
Reduced absorptive capacity
- Crohn’s disease
- Coeliac disease
- Intestinal resection
- Mucosal damage by drugs
Enzyme deficiencies
- Pancreatic insufficiency –> e.g. Cystic fibrosis
- Disaccharidase deficiency (primary alactasia/ secondary lactase deficiency)
- Bile deficiency (obstructive jaundice)
Drugs
- Antibiotics –> loose stools, increased intestinal transit time through gut, less nutrients absorbed
- Laxative
- Cholestyramine –> cholesterol reducing medication can affect gut absorption
Infection
- AIDS
- Gastroenteritis –> inflamed gut, diarrhoea, increase transit time
- Parasitic infection –> competition for nutrients from parasites
pH
- Achlorhydria –> increase stomachs pH so it is less acidic, more chance of getting infections from food eaten. Stomach acid is not killing of many bacteria
Food allergy/ intolerance –> loose stools, increase gut transit time
‘Detox’ products –> diarrhoea
How can you test for fat malabsorption?
Faecal fat test
- 70g fat/day for 6 days and stools collected
- Normal = <7g fat excreted per day
- Higher levels indicate malabsorption
Not done in practice –> more for research
Faecal fat microscopy
- Dye added to look for fat
- High amount indicates fat malabsorption
Breath tests
Faecal Elastase-1 test
What is steatorrhea?
Fatty stools/ oily residue
Floating stools
Pale/ yellow
Bulky
Loose
What is Faecal Elastase-1?
Pancreatic Elastase 1 or faecal elastase 1 is a human specific enzyme. FE-1 is enriched 5-6 fold in the faeces compared with pancreatic juices and can be used as an indicator of pancreatic exocrine function.
Identifies any pancreatic insufficiency
High marker –> poor pancreatic exocrine function
How can you test for carbohydrate malabsorption?
Hydrogen breath test
- Hydrogen produced by gut bacteria is unabsorbed disaccharides are present. Hydrogen is absorbed into blood and can be detected on the breath
Mucosal Lactase Assay
- Endoscopic biopsy
Lactose Tolerance Test
- Testing glucose absorption through lactose intake and checking blood glucose levels.
- If blood glucose levels haven’t increased then it means lactose hasn’t been broken down into glucose and hasn’t been absorbed or tolerated
What is breath testing in carbohydrate malabsorption tests?
Hydrogen breath test
- Hydrogen produced by gut bacteria is unabsorbed disaccharides are present. Hydrogen is absorbed into blood and can be detected on the breath
Many trusts/ GPs won’t pay for this service
Private companies may offer it
Used to detect lactose/ fructose intolerance
Need to avoid antibiotics for a certain time period prior to the testing
Follow a non-fermentable diet prior to testing (?)
Expensive
Not very reliable
What is the dietary treatment for malabsorption?
- Treat primary underlying disorder
- Dietary measures to relieve symptoms
- Replace water/ electrolyte losses –> especially for those with loose stools
- Restore optimal nutritional status –> especially with weight loss and protein loss
What is acute diarrhoea?
Causes?
Short term diarrhoea
- Infection
- Food allergy/ intolerance or excess intake
- Side-effect of drugs
- Anxiety
What is chronic diarrhoea?
Long term diarrhoea
- Crohn’s
- UC
- CD
- Cancer
- Short bowel disease
- IBS
- Stress and anxiety
- Drugs
- Infection
What is the management of diarrhoea?
- Investigate of underlying cause
- Maintain good fluid intake –> >2L/day
- Clear fluids better tolerated than milky drinks and fruit juices
- Oral rehydration solutions (for electrolytes) if severe e.g. Dioralyte
- Anti-motility drugs –> e.g. Codeine Phosphate, Loperamide
- Supplement drinks may be tolerated, if weight loss occurs, macronutrient and micronutrient loses - case of trail/ error
- Encourage an easily managed (light) diet –> plain foods
- Generally avoid foods high in fibre
How can fat malabsorption be managed?
- Pancreatic enzyme replacement therapy (PERT) are of benefit in pancreatic insufficiency e.g. Creon
- Reduce fat intake, ideally advise a moderate fat intake (50% usual) –> not usually advised to be super low, more just avoid super fatty foods to reduce risk of symptoms
- Don’t advise a very low diet as this can exacerbate weight loss and replace adequacy of intake of vitamin A, E, D and K
- Medium chain triglycerides can be useful occasionally to increase energy intake, but can cause osmotic diarrhoea
What enzymes does Pancreatic Enzyme Replacement Therapy (PERT) have?
Amylase, lipase, protease
- animal based –> porcine
Must bare in mind diets, cultural or religious preferences.
No plant based alternative
What is lactose intolerance?
Caused by a deficiency of the enzymes lactase, due to either an inherited or acquired condition. Causes osmotic effect in colon
How is carbohydrate (lactose) malabsorption managed?
Management depends on cause and severity of symptoms
- Avoid milk and milk products (temporary or permanent, depending on cause)
- Lactose free infant formula for infants, if formula fed
What are the symptoms of lactose malabsorption?
- Diarrhoea
- Stomach pain
- Bloating
- Nausea
- Frothy stools –> fermentation of lactose in gut
What can cause protein malabsorption?
How is it managed?
Protein losing enteropathies such as Crohn’s and untreated coeliac disease can cause a significant loss of protein and risk of negative nitrogen balance
- A high protein intake of 1-1.5g/kg/day may be required
- ONS potentially
Protein malabsorption may be due to deficiency of proteolytic enzymes in pancreatic insufficiency
- Dietary restriction of protein is not advised
- Pancreatic enzyme replacement therapy often necessary
What is IBS?
Symptoms?
Irritable Bowel Syndrome
Recurrent abdominal pain on average at least 1 day/ week in the last 3 months, associated with 2 or more of the following
- Related to a bowel movement
- Associated with a change in frequency of stool
- Associated with a change in the appearance of stool
ROME IV (2017) criteria
Chronic, relapsing and often life long
Estimated to affect 10-20% of population
Most commonly affects people between ages 20-30, more women
Many people do not seek medical help
Symptoms:
- Chronic fatigue
- Changed in bowel movements
- Abdominal pain
- Wind
- Bloating
- Constipation
- Diarrhoea
Sometimes back pain, depression
What are the sub-types of IBS?
IBS with constipation (IBS-C)
IBS with diarrhoea (IBS-D)
IBS with mixed bowel habits (IBS-M)
IBS unspecified (IBS-U)
Dietary treatment will depend upon which type of IBS.
What causes IBS?
Cause not really known
Often has triggers
- Stress
- Anxiety
- Major life event/ trauma
- Hormones
- Gut hypersensitivity/ disorder of gut brain axis
- Disturbed colonic motility
- Post infective bowel dysfunction e.g. from Salmonella
- Food intolerances/ diet
- Antibiotics
What are the red flags to rule out for IBS, according to NICE (2015)?
- Unintentional and unexplained weight loss
- Rectal bleeding
- A family history of bowel and ovarian cancer
- A change in bowel habit or looser stools persisting for more than 6 weeks in someone over the age of 60.
Blood tests –> FBC, CRP, coeliac screen
Faecal calprotectin
Colonoscopies
What is the treatment of IBS?
- Anti-diarrhoeal drygs e.g. Loperamdia
- Drugs for constipation
- Anti-spasmodic drugs e.g. buscopan, mebeverine
- Peppermint oil
- Antidepressants
- Lifestyle –> stress management, maintain/ increase activity levels