Chapter 9 - Diarrhea And Constipation Flashcards

1
Q

Osmotic diarrhea osmotic gap

A

> 50 mOsm/kg suggestive
100mOsm/kg specific

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

Secretory diarrhea osmotic gap

A

<50 mOsm/kg

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

Enterotoxigene E.coli mechanism

A

Adhere to specific glycoprotein receptors on the intact microvillous membrane by means of pili which permits colonization

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

Enteropathogenic E.coli mechanism

A

Obliterate microvilli, producing pedestals to which they adhere

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

Shigella mechanism

A

Internalized by endocytosis and spreads laterally from cell to cell

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

Salmonella mechanism

A

Penetrates the brush border and tight junction to gain access not only to the mucosa, but also to the bloodstream

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

Cholera toxin mechanisms

A
  • binds to apical membrane, internalized, cAMP activation and production. Blocks sodium absorption and stimulates chloride secretion by the entorocytes
  • interacts with enteroendocrine cells and enteric nervous system altering electrolyte transport and motility.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

E.coli STa toxin mechanism

A

Ligand to brush-border receptor guanylin and uroguanylin, endogenous regulatory peptides produced by enterocytes and distributed intraluminally. Guanylate Cyclase and cGMP production causing Cl secretion.

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

Campylobacter Jejuni mechanism

A

Often tissue invasion and severe colitis mimicking UC

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

E.coli O157:H7: clinical manifestation and source

A

Hemorrhagic segmental colitis
Hemolytic uremic syndrome

Undercooked hamburger or other foods

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

C.difficile mechanism

A

Cytotoxin production that kills enterocytes and produces pseudomembrane colitis

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

Rome IV criteria IBS

A

Abdominal pain with 2/3:
- related to defecation
- associated with change of stool frequency
- associated with change of stool consistency/form

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

Bile acid malabsorption diagnostic strategy

A
  • SeCHAT retention
  • C4 or FGF-19 assay
  • trial of bile acid sequestrant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

SIBO diagnostic strategy

A

Quantitative culture of small intestinal aspirate
Breath hydrogen testing
Trial antibiotic therapy

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

What does pH of stoo < 6 indicate?

A

Excess carbohydrate fermentation in the colon

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

How much fat to ingest per day for accurate fat output testing?

A

70-120g

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

Possible bacteria for chronic diarrhea

A

Aeromonas and pleisiomonas

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

Protozoal pathogens in stool requiring modified acid-fast or safranin staining

A

Cryptosporidium, cyclospora and cystoisospora

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

Type 1 bile acid diarrhea

A

Après resection iléale ou dysfonctionnement iléale

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

Type 2 bile acid diarrhea

A

Idiopathic
30% patients with IBS-D or functional diarrhea
Due to defective FGF-19 feedback
Serum FGF19 bas et C4 élevé

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

Type 3 bile acid diarrhea

A

Associated to other diseases in which bile acid malabsorption might play a role.
- Post-Cholecystectomy
- postvagotomy
- SIBO
- post-radiation diarrhea

22
Q

Magnesium associated osmotic diarrhea diagnosis

A

Excretion > 15 mmol (30mEq)
Concentration in stool water > 45 mmol/l (90mEq/l)

23
Q

Malabsorption hydrocarbures diagnostic

A

Gap osmotic fecal >50mOsm/kg
PH selles <6
Anamnese alimentaire

24
Q

Chronic inflammatory diarrhea: pathogens

A

C.difficile
CMV
Entamoeba histolytica
Tuberculose

25
Q

Steatorrhea definition

A

Excessive loss of fat in the stool >7g ou 9% de la prise en 24h (pas valable si diarrhée)

26
Q

Major causes of steatorrhea

A

Mucosal disease
Pancreatic exocrine insufficiency
Lack of bile

27
Q

Eluxadoline

A

Delta-opiate receptor agonist
Do not give if pancreatitis, alcohol abuse or st.p. Cholecystectomy

28
Q

Crofelemer: mechanism and indication

A

Inhibits electrolyte secretion in the intestine (chloride channel blocker)
Approved for HIV therapy induced diarrhea

29
Q

Différence entre IBS-C et constipation chronique idiopathique

A

La douleur

30
Q

Temps de transit dans le colon

A

24-30 du caecum au rectum

31
Q

Qu’arrive-t-il au fibre pendant le transit dans le colon

A

Fermenté en gaz et en acides gras à chaîne courte par la flore bactérienne

32
Q

Quantité de selles normales par 24h

A

80-120 g/ 24h

33
Q

Temps de transit colon: technique et résultat normal

A

Capsule qui contient 24 radiomarqueurs, Rx abdomen 5 jours après. Rétention de > 5 marqueurs après 5 jours est anormal.

34
Q

Test d’expulsion: quand est-ce que c’est anormal

A

Si échec d’expulsion d’un ballon contenant 50 ml d’eau dans les 60 à 120 secondes

35
Q

Cible de fibre par jour

A

20-30g/j

36
Q

Lubiprostone: mechanism

A

Ouvre les canaux chloriques ClC-2 ce qui augmente la sécrétion luminale, change la perméabilité épithéliale ou aussi effet sur la fonction nrégulatoire de l’intestin.

37
Q

Lubiprostone dose

A

Constipation: 24 mcg 2x/j
IBS-C: 8 mcg 2x/j

38
Q

Linaclotide: nom commercial

A

Constella

39
Q

Linaclotide: mécanisme

A

Augmente la sécrétion de chlore en ouvre les canaux CFTR via cGMP
Possible effet inhibiteur sur les nerfs nociceptifs du systeme nerveux entérique

40
Q

Linaclotide: dose

A

Constipation: 72 mcg ou 145 mcg par jour
IBS-C: 290 mcg/j

41
Q

Plecanatide: mécanisme

A

Analogue d’uroguanylin, effet similaire à Linaclotide avec ouverture des CFTR.
PH dépendant, agit seulement au niveau du grele donc fait possiblement moins de diarrhées

42
Q

Plecanatide: nom commercial

A

Trulance

43
Q

Plecanatide: dosage

A

3mg/j (Constipation et IBS-C)

44
Q

Tenapanor

A

Inhibiteur de NHE3 (échangeur de sodium de la muqueuse intestinale). Diminue absorption de sodium ce qui peut améliorer les symptomes d’IBS-C

45
Q

Tenapanor: dose

A

Constipation: 10mg/j
IBS-C: 50 mg 2x/j

46
Q

Liste de sécrétagogue:

A

Lubiprostone
Linaclotide
Plecanatide
Tenapanor

47
Q

Liste de traitements systémiques de la constipation

A

Bethanechol
Misoprostol
Colchicine
Prucalopride

48
Q

Prucalopride: nom commercial

A

Resolor

49
Q

Prucalopride: mécanisme

A
  • agoniste complet des récepteurs 5-HT4
  • augmente le péristaltisme et diminue la douleur viscérale sans agir sur les récepteur cardiaques
50
Q

Prucalopride: dose

A

2mg/j

51
Q

Antagonistes mu périphériques

A

Méthylnaltrexone
Naloxegol
Nalmétidine

52
Q

Methylnaltrexone: nom commercial

A

Relistor