Diarrhoea Gastro Tutorial (2) Flashcards
Commenest cause of gastroenteritis in UK
Campylobacter - common cause of bloody diarrhoea
Origin of Campylobacter bacteria
- Chicken guts
- Spread
Abx for severe Campylobacter infection
Clarithromycin - only if very unwell, if not conservative management
Treatment and investigation for suspected UC
- Colonoscopy
- Corticosteroids in flare up - prednisolone
- 80% of people feel 80% better after 2 weeks of steroids
- If no improvement - complication can be toxic megacolon
Toxic megacolon management
- Fluids - 6L probably for 24hrs (3x saline and 3x dextrose, 20mmol of K+ added to each bag so 120 total due to high K+ losses)
- Biologics - Anti-TNF alpha eg Infliximab to try and save colon
- If no improvement in 24-48hrs –> colectomy
- But doing CRP and abdo x-ray regularly to see improvement
What is a Crohn’s mass and how to manage ?
- Inflamed loops of small bowel stick together + omentum = hard
- If perforates can cause abscess - assess this using CT scan
- If just Crohns - steroids
- If abscess - surgery needed
Differentials for mass felt in RIF with diarrhoea and abdo pain
- Crohns
- GI cancer
- Constipation - check if caecum is indentable?
- Chronic appendicitis?
Test to differentiate IBS and IBD
- Faecal calprotectin - if negative likely to not be IBD as VERY sensitive test
- BUT cannot tell between acute infection and chronic inflammation so careful as someone with IBS may just have gastroenteritis so test comes back +ve
Test to rule out coeliac disease
- Anti tissue transglutaminase antibody blood test
- Need to do total IgA alongside this - otherwise useless if low
Definitive test for coeliac disease and findings
- Endoscopy of 2nd part of duodenum
- Increased lymphocytes
- Flattened villi
How to assess whether diarrhoea is overflow diarrhoea or IBS?
- Take bloating history
- If bloating not present in morning but then worsens throughout day = IBS
- If bloating present overnight until morning = constipation overflow diarrhoea. Bloating will not subside until stool is passed
Causes of constipation
- Avoiding poo reflex too often - this then stops happening as often and feel need to go less and less –> constipation
- Diet - lack fibre
- Lack exercise
Cause of long term steatorrhoea and weight loss after visit to foreign country
- Giardia lamblia - parasite infection
- Causes malabsorption (hence steatorrhoea due to lipid in faeces) from presence of Giardia
- From contaminated water sources
Treatment for Giardia infection
Metronidazole
How to know when diarrhoea is caused by toxin
Effects are immediate - very fast
Usually contaminated by Staphylococcus on skin - produces toxins with are heat stable
Everytime reheat and cool food = multiplies, more and more toxin
Eg esp with kebabs
How to test for C.diff?
C difficile toxin A and B test on stool sample via PCR or enzyme immunoassay
C.difficile antigen (specifically glutamate dehydrogenase)
Treatment for C.diff
Oral vancomycin or metronidazole
2nd line -Fidaxomicin
Fluids for C.diff
- only large bowel affected
- Not too dehydrated
- 2-3L should be enough of half saline half dextrose with 40K+ added
Likelihood of second c.diff infection after treatment
High - spores are resistant to abx, they germinate a lot when gut is treated with antibiotics as no flora to compete with
Management of second C.diff infection
- Do nothing if mild - let GI tract regain flora
- If likely to be severe - treat with prophylactic vancomycin for 2 weeks following infection treatment
Other cause of diarrhoea post abx apart from C.diff
The antibiotics themselves - can cause diarrhoea
How can a low MCV be caused by GI issue?
Malabsorption - causes iron deficiency
= iron deficiency anaemia
Main causes of malabsorption in UK
- Crohns
- Coeliac disease
- Pacreatitis - eg from alcohol or gall stones
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Test for pancreatitis
Faecal elastase
