Diarrhoea and Malabsorption Flashcards Preview

Hugh's MD2 Intersession 1 > Diarrhoea and Malabsorption > Flashcards

Flashcards in Diarrhoea and Malabsorption Deck (18)
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1

How is IBS treated?

Low FODMAP diet

 

2

What are the red flags of IBS diagnosis?

>45

Bloody diarrhoea

Nocturnal symptoms

Weight loss

3

What must be excluded before the diagnosis of IBS can be made?

IBD

Coeliacs

Colorectal cancer

4

How is the diagnosis of coeliacs made?

Positive transglutaminase abs - DGP (deamidated gliadin peptide)

Biopsy demonstrating villous atropy, crypt hyperplasia, and intraepithelial lymphocytes while on gluten diet

- and resolution of these when off the gluten

5

What does faecal elastase reflect?

Exocrine failure of the pancrease

6

What is the pathophysiology of IBS?

Serotonin is the key mediator - disordered intestinal motility

7

What causes secretory diarrhoea? What are the characterists of it?

Active secretion of anions by enterocytes typically due to bacterial toxin, hyperthyroidism

 

Large volume, persist during fasting

No leukocytes

Calprotectin is normal

8

Where is iron absorbed?

In the proximal small intestine

9

Describe fluid absorption and secretion in the GIT

9L enters the tract

7L is absorbed in the SI

1.8L is absorbed in the large intestine

200ml passes in stool

10

Why might you get steatorrhoea in Crohn's?

Failure of bile salt reabsorption in the terminal ileum

11

How is IBS diagnosed?

Rome III crieria

- Symptoms > 3 months

- Recurrent abdominal discomfort associated with

> Relief with defaecation

> Change in stool colour and frequency 

12

How do you test someone for coeliacs if they're already on a gluten free diet?

HLA-DQ2 and 8 genotype

6 week gluten challenge

13

What are some causes of increased intestinal motility?

Thyrotoxicosis

IBS

Diabetic neuropathy

14

What are some mechanisms of intraluminal maldigestion?

Mechanical failure of mixing eg post gastrectomy

Decreased nutrient availability 

Defective nutrient hydrolysis - eg pancreatic insufficiency

Reduced fat solubilisation

 

 

15

What is faecal calprotectin a marker of?

Gastrointestinal inflammation

16

What are the mechanisms of diarrhoea?

Osmotic

Secretory

Inflammation

Altered motility

17

What the mechanism and cause of inflammatory diarrhoea and what are the characteristics of it?

Increased permeability of the mucosa causing exudate of blood, pus or protein

Invasive bacteria (eg Shigella, Salmonella), Entamoeba histolytica, CMV colitis, IBD

 

Small volume +/- blood and pus

Associated with tenesmus, urgency and constitual symptoms

18

What is a common cause of osmotic diarrhoea? What are the characterists of it?

Presence of excess unabsorbed carbohydrates

- eg Fermentable carbohydrate malabsorption - FODMAPs

 

< 1L

Stops with fasting

Increased stool osmotic gap