Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CSI 1b > Diarrhoea > Flashcards

Diarrhoea Flashcards

(69 cards)

Start Studying
1
Q

Diarrhoea definition? Passage of…

A
  • three or more loose or liquid stools per 24 hours, and/or
  • stools that are more frequent than what is normal for the individual lasting <14, and/or
  • stool weight greater than 200 g/day

decreased absorption or increased secretion of fluid and electrolytes, or increase in bowel motility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Diarrhoea duration classification?

A
  • acute (<14 days)
  • persistent (>14 days)
  • chronic (>4 weeks)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much fluid enters GI tract every day?

A

10 litres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the major site for re-absorption?

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How much fluid is reabsorbed?

A

About 99% reabsorbed

0.1 litre excreted in faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Inflammatory diarrhoea causes?

A

Can be due to bacterial, viral, or parasitic infection

May develop early in course of bowel ischaemia, radiation injury, or inflammatory bowel disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Inflammatory diarrhoea associated symptoms?

A

Mucoid and bloody stool
Tenesmus
Fever
Severe cramps abdominal pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Infectious inflammatory diarrhoea? Volume and bowel movements

A

Small volume
Frequent bowel movements

does not usually result in volume depletion in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Most common bacterial causes of infectious diarrhoea? In US

A

Campylobacter
Salmonella
Shigella
E. coli
Clostridium difficule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Other causes of infectious diarrhoea?

A

Viruses (more common among children who attend day care centres)
Protozoa and parasites (common causes of acute diarrhoea in developing countries)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Examination of stool in inflammatory diarrhoea?

A

May show leukocytes
Tests for occult blood may be positive
Faecal calprotectin

test for faecal leukocytes - plagued by high rate of false-negatives but positive test very informative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Histology of GI tract in inflammatory diarrhoea?

A

Abnormal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Non-inflammatory diarrhoea? Volume, frequency and symptoms compared to inflammatory

A

Watery, large-volume, frequent stool (>10 to 20 per day)

volume depletion is possible due to high volume and frequency of bowel movements
no tenesmus, blood in stool, fever, or faecal leukocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Histology of GI tract in non-inflammatory diarrhoea?

A

Preserved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Non-inflammatory diarrhoea subdivisions?

A

Secretory diarrhoea
Osmotic diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Secretory diarrhoea? Mechanism and osmotic gap

A

Altered transport of ions across mucosa -> increased secretion and decreased absorption of fluids and electrolytes from GI tract (esp. small intestine)

doesn’t decrease by fasting
low stool osmotic gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Causes of secretory diarrhoea?

A

Enterotoxins
Hormonal agents
Laxative use, intestinal resection, bile salts, fatty acids

also seen in chronic diarrhoea with coeliac sprue, collagenous colitis, hyperthyroidism, and carcinoid tumours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Enterotoxin causes of secretory diarrhoea?

A

Vibrio cholera
Staph. a
Enterotoxigenic E. coli
Possibly HIV and rotavirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Hormonal causes of secretory diarrhoea?

A

Vaso-activate intestinal peptide
Small-cell cancer of the lung
Neuroblastoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Osmotic diarrhoea? Volume and mechanism

A

Stool volume relatively small, diarrhoea improves with fasting
Results from presence of unabsorbed solute (magnesium, sorbitol, mannitol) in intestinal tract that causes increased secretion of liquids into gut lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Osmotic diarrhoea tests and osmotic gap?

A

Stool electrolytes shows increased osmotic gap (>50)
Stool is always isosmotic (260-290 mOsm/L)

so stool osmotic gap test could differentiate between osmotic and secretory diarrhoea
high stool osmotic gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Osmotic diarrhoea subdivisions?

A

Maldigestion
Malabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Transcellular vs paracellular transport?

A

Transcellular transport - when solutes travel through the cell
Paracellular transport - when solutes travel around the cell (e.g. through gap junctions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Water secretion into lumen?

A
  1. Chloride channels on luminal side activated, chroride ions transported into cellular lumen
  2. Causes paracellular transport of sodium from interstitial space -> lumen
  3. This creates osmotic gradient - water follows the solute so water is secreted into the lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Water absorption?
Sodium transporters on luminal and interstitial side cause transcellular sodium transport into capillaries - water follows into capillaries (through enterocytes) *often on empty stomach*
26
How does infection cause inflammatory diarrhoea?
Reduced absorption Pathogens affect interstitial lining -> affects transport and reduces water absorption *causes water retention in lumen -> diarrhoea*
27
Secretory diarrhoea? Mechanism and 2 causes
Increased secretion *increased activation of chloride transporters -> increased secretion of water into lumen -> diarrhoea* Causes - cholera toxin, laxatives…
28
How does lactose intolerance cause maldigestion diarrhoea (osmotic)
Lactose not being digested into glucose (and galactose) so process of sodium absorption and water absorption does not happen
29
How does pancreatic exocrine insufficiency cause maldigestion diarrhoea (osmotic)?
Problem with digestive enzymes - insufficient digestion of food -> sodium transporters or enterocytes not activated -> reduces transport + absorption of sodium -> reduced absorption of water and diarrhoea
30
Malabsorption diarrhoea causes?
Sorbitol (found in proons) Surgical resection Bacterial overgrowth *causes water retention in lumen*
31
Reduced absorption causes of diarrhoea?
Inflammatory diarrhoea Osmotic diarrhoea - maldigestion and malabsorption
32
Cause of increased secretion diarrhoea?
Secretory diarrhoea
33
Conjugates on drugs?
Drugs with large conjugates attached to them which can be digested in specific place e.g. colon - would be helpful if inflammation in colon
34
Drugs to improve absorption in small intestine considerations and side effects?
Small intestine structures allow for maximal absorption, leading to high systemic availability of any absorbed medication *causes increased side effect profile of medications due to enhanced absorption*
35
Anti-inflammatory drugs problem?
Anti-inflammatory drugs are designed for colon absorption, so only effective if inflammation causing diarrhoea originates in colon *tend to be potent drugs with significant side effects*
36
Targeting transporters for secretory diarrhoea?
Intestinal transporters implicated in diarrhoea process, e.g. SGLT-2, sodium channels, sodium-glucose transporter Targets are expressed throughout the body (causing potential side effects) *aim is to reduce secretion and/or to increase absorption*
37
Maldigestion drugs difficulty and strategies?
Difficult to enhance endogenous enzyme activity Exogenous enzymes are susceptible to digestive process Strategies - enteric coating, probiotics, gene therapy
38
Gene therapy risks?
Unwanted immune response, incorrect cell targeting
39
IBS symptoms?
*Alternating constipation and diarrhoea* *Bloating* Abdominal pain Faecal urgency Mucus in stool Fatigue
40
IBD symptoms?
*Weight loss* *Fever* *Blood in stool* *raised faecal calprotectin unlike in IBS* Abdominal pain Faecal urgency Mucus in stool Fatigue
41
IBS and IBD shared symptoms?
Abdominal pain Faecal urgency Mucus in stool Fatigue
42
Organic cause of diarrhoea investigations?
- FBC - check for amaemia and signs of inflammation, LFT, pancreatic enzymes, TSH, ESR (acute inflammation), CA-125 (ovarian cancer) - Urea and electrolytes - check renal function and electrolyte status - CRP - look for signs of infection/inflammation - Stool MC&S (for infective), qFIT (microscopic blood in stool), faecal calprotectin (inflammation in bowel) - X-ray, colonoscopy
43
Stool tests for organic diarrhoea?
Stool tests - routine microbiology, ova cysts and parasites (3 specimens a min of 2 days apart as ova and cysts are shed intermittently), calprotectin
44
Blood tests for diarrhoea?
FBC, U&E, LFTs, Ca2+, B12, folate, ferritin, TFTs, ESR/CRP, test for coeliac *Faecal calprotectin if bloods show abnormality*
45
Types of inflammatory bowel disease?
Crohn’s disease Ulcerative colitis
46
Features of Crohn’s vs ulcerative colitis? Lesions and layers
Crohn’s - Non-continuous lesions or “skip lesions” in Crohn’s, cobblestone appearance. Affects all layers of bowel UC - Continuous and uniform, no breaks of normal bowel. Affects mucosa (and submucosa) only
47
Location of Crohn’s vs ulcerative colitis?
Crohn’s - anywhere, mouth to anus in skip lesions (commonly starts at terminal ileum) UC - primarily affects colon and rectum, usually starts in rectum then spreads upwards. Only affects large bowel
48
Depth of inflammation in Crohn’s vs ulcerative colitis?
Crohn’s - transmural involvement, affects all layers of intestinal wall UC - just mucosa, continuous inflammation
49
Granulomas in Crohn’s vs ulcerative colitis?
More common in Crohn’s (non-caseating and increased goblet cells) *Could be due to more macrophages in Crohn’s, compared to more neutrophils in UC which have a shorter half life*
50
Crypt abscesses in Crohn’s vs ulcerative colitis?
More common in Crohn’s *crypt distortion without branching in UC*
51
Ulcerations and fistulas in Crohn’s vs ulcerative colitis?
Crohn’s - fistulas and deep ulcerations may be present, perianal area fistulas or skin tags, more likely perianal involvement UC - superficial ulcerations without fistulas, broad-based ulcers and pseudopolyps common
52
Conservative management for Crohn’s disease?
Lifestyle (smoking cessation, avoiding foods that trigger flare ups so dietary modification) *reducing fibre* High calorie supplements
53
Medical management to induce remission of Crohn’s?
Steroids (oral - prednisolone, IV - hydrocortisone) for a flare up Aminosalicylate Azathioprine/mercaptopurine Infliximab/adalimumab
54
Medical management to maintain remission of Crohn’s?
Immunosuppressants - Azathioprine/mercaptopurine - Methotrexate
55
Surgical management of Crohn’s?
Bowel resection
56
Main symptoms of Crohn’s?
Diarrhoea Stomach aches and cramps Blood in poo Tiredness Weight loss *high temp, nausea and vomiting, joint pains, sore and red eyes, patches of painful, red, swollen skin, mouth ulcers*
57
Causes of Crohn’s?
Genes Autoimmune Smoking Previous stomach bug Abnormal balance of gut bacteria
58
Specialist tests for Crohn’s?
Colonoscopy Biopsy MRI or CT
59
Treatment for Crohn’s? (NHS website)
Steroids Liquid diet Immunosuppressants Biological medicines Surgery
60
Living with Crohn’s? (NHS website)
*ibuprofen can make it worse* Vaccinations should be taken Tell GP about pregnancy Contraception may not work the same (OCP) Cancer screening - BOWEL CANCER
61
Normal stool osmotic gap values?
Between 50 and 100
62
Smoking in Crohn’s vs UC?
Smoking risk factor for Crohn’s Smoking protective against UC
63
Only diagnostic investigations for IBD?
Colonoscopy and biopsy
64
Corticosteroid example for Crohn’s?
Prednisolone
65
Immunosuppressants for Crohn’s?
- Azathioprine - Mercaptopurine - Methotrexate
66
Biologics for Crohn’s?
- Adalimumab - Infliximab
67
Lifestyle precautions for Crohn’s? Diet, medication, recommended, avoid
Diet - enteral nutrition for children, healthy for adults, stop smoking Medication - NSAIDs can interact with Crohn’s medication Recommended - flu and pneumococcal jab AVOID - live vaccines
68
Maldigestion diarrhoea mechanism and 2 causes?
Impaired digestion of nutrients within intestinal lumen or brush border membrane of mucosal epithelial cells. In pancreatic exocrine insufficiency and lactase deficiency.
69
Malabsorption diarrhoea? Mechanism and some causes
Impaired absorption of nutrients In small bowel bacterial overgrowth, mesenteric ischaemia, post bowel resection, mucosal disease (coeliac)

CSI 1b (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions