Common GI Tract disorders Flashcards
1
Q
What is Diarrhoea?
A
- Defined as passage of >200g faeces per day
- Increases in faecal mass of 500 – 1000g /day require attention
- Needs to be more severe to result in dehydration
2
Q
What are the results of Diarrhoea physiologically?
A
- Lower GI losses results in loss of bicarbonate - metabolic acidosis
- Dehydration - increased Urea
- Electrolyte disturbances – especially decreased K+ and Mg2+, decreased HCO3
3
Q
What are the different types of Diarrhoea?
A
- Osmotic: Due to solution of high osmotic potential, generally salt or sugar. Water is drawn from the body to equilibrate the chyme. Can also be due to malabsorption
- Secretory: Increased secretion or reduced absorption of water and ions e.g. enterotoxins (such as cholera) open membrane channels leading to export of water, Na, K and HCO3 into the intestine
- Inflammatory: Damage to intestinal mucosa e.g Ulcerative Colitis/Crohn’s disease or infective e.g Shigella (Dysentary)
4
Q
What results from Vomiting physiologically?
A
One of the most common causes is gastroenteritis leading to upper GI losses
- Loss of acid – increased bicarbonate
- Decreased chloride - metabolic alkalosis
- Dehydration can result in low K (2°Hyperaldosteronism)
5
Q
What can causes Upper GI bleeds?
A
- Peptic ulcer
- Oesophageal varices
- Gastric erosions
- Gastric cancer (rarely )
6
Q
What is the results of Upper GI bleeds physiologically?
A
- Red blood cells released and reabsorbed
- Increased potassium (from intracellular release)
- Increased urea from protein metabolism
- Raised urea:creatinine ratio
7
Q
What is Irritable Bowel Syndrome?
A
- Bowel disorder with no detectable organic cause
- Signs and symptoms include cramping, abdominal pain, bloating, gas and diarrhoea or constipation
- Does not cause changes to the bowel tissue, does not increase risk of colorectal cancer
- Diagnosis of exclusion
8
Q
What is Inflammatory Bowel Disease?
A
- Similar symptoms to IBS
- Caused by chronic inflammation of the digestive tract
- Crohn’s Disease and Ulcerative colitis
9
Q
What are features of Crohns Disease?
A
- Age of onset between 15-35 years of age
- Symptoms: Abdominal pain, Diarrhoea, Weight Loss and Fatigue, Bloody stool, malnutrition
- Can affect any part of GI tract from mouth to anus
- Most commonly starts in terminal ileum
10
Q
What are features of Ulcerative Colitis?
A
- Age of onset between 15-35 years of age
- Symptoms: Stool Urgency, Fatigue, Increased Bowel Movements, Mucous In Stools, Nocturnal Bowel Movements, Abdominal pain
- Restricted to colon and rectum
11
Q
What are some biochemical tests for Inflammatory Bowel Disease?
A
- Faecal calprotectin identifies patients who require colonoscopy
- CRP/ESR can give an indication of the level of inflammation
- Nutritional assessment
12
Q
What is Coeliac Disease?
A
Gluten sensitive enteropathy
- Wheat protein contains gliadin. Gliadin metabolised by tissue transglutaminase
- In Coeliac disease, an autoimmune reaction happens. Upon exposure to Gliadin, there is an immunological response to Tissue transglutaminase.
13
Q
How is Coeliac Disease screened?
A
- Screened by ELISA (TTG)
- Histology to confirm
14
Q
How is Bowel Cancer screened biochemically?
A
- National screening programme for men and women aged 60 to 74
- Offered test ever 2 years
- Uses Faecal Immunochemical Test (FIT)
- Detects small amounts of faecal occult blood
15
Q
What is intestinal failure?
A
- Defined as intestinal failure when the ability of intestine to absorb fluids and nutrients threaten’s the health of patient
- Intestines have considerable reserve capacity
- Maybe short term while awaiting surgery on the small intestine
