Diarrhoea Flashcards
What is defined as acute diarrhoea
Lasting less than 2 weeks
Signs of moderate dehydration
Apathy Dizziness Tiredness Muscle cramps Dry tongue/ sunken eyes Reduced skin turgor Oliguria
Signs of severe dehydration
Profound apathy Weakness Confusion -> coma Shock (hypovolaemic) Tachycardia SBP <90 Anuria
Lower GI red flags
Age>50 Rectal bleeding Recent change in bowel habit Nocturnal symptoms Unexplained/ unintentional weight loss Iron deficiency anaemia Family history of colorectal cancer/ IBD
Differences between bloody and non-bloody diarrhoea
Non-bloody tends to be from small bowel,
Non-bloody produces large volumes
Non-bloody is typically painless
Causes of non-bloody diarrhoea
Infection - gastroenteritis Different medications e.g. antacids, NSAIDs, PPIs, antibiotics, metformin, thyroxine Hyperthyroidism Malabsorption IBS Chron's Overflow diarrhoea after constipation
What is a common cause of c.diff infection
Clindamycin
Broad spectrum antibiotics e.g. meropenem
Features of cholera
Very watery diarrhoea
May cause hypovolaemic shock
NO abdominal pain or fever
Parasites that cause diarrhoea…
Giardia
Entamoeba
Cryptosporium
*Causes prolonged diarrhoea for >14 days, usually without vomiting
Viruses that cause diarrhoea…
Rotavirus - commonly in children, self limiting (7d course)
Norovirus - mainly vomiting followed by diarrhoea (1-2d)
Causes of bloody diarrhoea…
Gastroenteritis - campylobacter jejuni, salmonella, e coli, shigella
Diverticulitis
Ulcerative colitis
Ischaemic colitis
Fetaures of campylobacter jejuni infection
Profuse watery bloody diarrhoea
Fever
Cramps
24 hour prodrome of flu-like illness
Features of shigella infection
Acute watery diarrhoea
May contain pus, mucus, blood
Fever and abdominal pain
Duration of 3 days
Management of mild diarrhoea
- FLUID BALANCE AND ELECTROLYTE SUPPLEMENTATION
- Anti-secretory medications - used with rehydration treatment
- May need to admit if severely dehydrated, and unable to retain fluids
- Antimotlity agent e.g. loperamide 2mg
- Antispasmodics e.g. hyoscine butylbromide
- Antibiotics can be used in infectious cases (giardiasis, campylobacter, shigella)
When should you report to public health?
Suspected public health hazard e.g. food handlers
Diarrhoea outbreak - need to identify organism
Specific organisms causing damage - e.g. E.coli O157
What counts as chronic diarrhoea
Passing abnormally large volumes of loose stools for >14 days
Differentials for chronic diarrhoea…
- Large bowel: diverticulitis, colon cancer, colitis (UC, Chron’s, ischaemic colitis)
- Small bowel: malabsorption (coeliac disease, Whipple’s, CF), lactose intolerance, IBS
- Endocrine: Hyperthyroidism, autonomic neuropathy from Diabetes, Addsion’s disease
- Chronic infection e.g. giardiasis
Red flags for chronic diarrhoea…
- Weight loss
- Rectal bleeding
- Diarrhoea persisting >6 weeks in patients >60y/o
- Family history of ovarian/bowel cancer
- Abdominal/ rectal mass
- Anaemia in males/ post-menopausal women
- Raised inflammatory markers
Investigations for chronic diarrhoea…
- Blood tests: FBC, LFT, TFT, ESR/ CRP
- Malabsorption tests: calcium, B12, folate, iron studies
- Antibody tests: coeliac disease
- Stool sample for MC&S and OCP
- Faecal elastase test in stool (for pancreatic insufficiency)
- Endoscopy
- Barium follow through
- Pancreatic CT scanning
- Flexible sigmoidoscopy
Polymorphs on direct faecal smear indicates…
Shigella
Campylobacter
E.coli
Management of gastroenteritis
- Depends on clinical status of patient - if they are not systemically unwell - admission is not necessary
- Patients that develop diarrhoea need to be isolated in side room with ID consultant notified
- Barrier nursing
- Oral rehydration therapy/ IV fluids
- Symptomatic management: prochlorperazine (anti-emetic), loperamide
- Antibiotics (mainly only in immunocompromised / severe infection)
What antibiotic is used to treat traveller’s diarrhoea?
- Ciprofloxacin 500mg BD for 3 days
OR - Azithromycin 500mg BD for 3 days
How is c.difficile diagnosed?
- C.dif toxin (A+B toxins) stool analysis
Management plan for c.difficile…
- Isolate the patient and barrier nursing
- Moderate disease= metronidazole 500mg TDS for 10/7
- Severe disease= vancomycin 125mg QDS for 10/7
What treatment can be used if antibiotics are not successful in recurrent c. diff infection and how does it work?
FAECAL TRANSPLANTATION
- Faeces from donor is screened for numerous pathogens etc before being processed.
- Sample is processed into tablets or liquird
- Sample is delivered to gut via oral/nasal or colonoscope
- Faecal sample delivers beneficial gut bacteria which begin to colonise to restore a health community - competing with c. diff
What is pseudomembranous colitis?
Swelling or inflammation of large intestine due to c.diff infection , leading to a pseudomembrane forming by a viscous collection of inflammatory cells.
May go on to cause toxic megacolon or bowel perforation
What is the pathophysiology of toxic megacolon?
Form of acute colonic distension caused by inflammation/ damage to the colonic wall. There is destruction of ganglion cells and nerve fibres which damages the enteric nervous system.
The affected area of the colon has loss of tone and motility which can lead to further complications like faecal stasis and perforation.
What is the treatment for toxic megacolon?
Decompression of the bowel - removal of gas and substances filling the colon.
Colectomy (ideally subtotal with end ileostomy) - in patients who have not shown improvement
Corticosteroids to suppress inflammatory reaction - if caused by IBD.
How is pseudomembranous colitis identified from flexible sigmoidoscopy?
Yellow adherent plaques present on inflamed mucosa.
What are the subclasses of IBS
IBS C = constipation dominant
IBS D= diarrhoea dominant
IBS M= mixed
What is the Rome IV Criteria for diagnosing IBS?
Recurrent abdominal pain for at least 1 day per week over the last 3 months , associated with at least 2 of 3:
- Related to defecation
- Associated with change in frequency of stool
- Associated with a change in form of stool
What is the Manning Criteria for diagnosing IBS?
3 or more of the following criteria required?
- Onset of pain linked to more frequent bowel movements
- Looser stools associated with onset of pain
- Pain relieved by passage of stool
- Noticeable abdominal bloating
- Sensation of incomplete evacuation >25% of the time
- Diarrhoea with mucus >25% of the time
Investigations for IBS…
- FBC: anaemia is a red flag and would make IBS diagnosis unlikely
- ESR and CRP: markers of inflammation / infection
- Coeliac screen (EMA and TTG)
- Foecal calprotecin: rule out IBD
- CA-125: suspicion of ovarian cancer
- Other Ix include: TFTs, imaging, FOBt, Faecal OCP and MC&S, hydrogen breath test
Management of IBS…
Reassurance and information about condition is important
Conservative:
- Reduction in stress
- Increased physical activity
- Drink fluids, more fibre in diet
Medical:
- Loperamide for diarrhoea
- Laxatives for constipation (avoid lactulose)
- Antispasmodics for abdominal pain e.g. hyoscine butylobromide
Main features of Chron’s disease…
- Can occur across whole of GIT
- Skip lesions present - not continuous
- Thickened bowel wall - cobblestone
- Strictures, deep fissures, fistulae present
- Granulomatous formation
- Transmural inflammation through to muscle layer
- Increased WBC count
- Associated with pANCA antibodies
Main features of Ulcerative Colitis
- Present only in large bowel and rectum
- Continuous lesion present
- Thinning of the bowel wall
- No strictures, fissures or fistulae
- No granulomas
- Inflammation confined to mucosa
- Increased WBC count
- Associated with ASCA antibodies
What areas of GIT are most commonly affected in Chron’s?
Proximal colon and terminal ileum
Presentation of Chron’s…
- Chronic diarrhoea - may be associated with blood, mucus, abdominal pain
- Weight loss
- Aphthous (small shallow lesions) ulcers of mouth
- Signs of anaemia
- Anal and perianal lesions
- Clubbing, erythema nodosum
- Conjunctivitis, episcleritis, uveitis
- Enteropathic arthritis
What is the first line investigation for diagnosing Chron’s?
Ileocolonoscopy with biopsy from terminal ileum –> histological analysis of sample
Management of Chron’s flare up…
-Initial A-E assessment : IV fluids, blood tests - CRP
- AXR to rule out toxic megacolon
- Induction of remission with oral/ IV corticosteroids
-Maintenance of remission:
>Immunosuprresion e.g. azothioprine, methotrexate (not used in UC)
>Biological therapy= infliximab (anti-TNF), usteknimab (anti IL-23)
>Surgery for complications e.g. fistulae, strictures, abcesses - resection of affected area
Management of stable Chron’s…
In patients where remission was induced by steroids - maintenance therapy with AZA is possible
Methotrexate/ folate can be used if AZA is not tolerated
Some patients will require continuation of anti-TNF treatment
*3 monthly monitoring of renal, liver and bone marrow function is important.
Presentation of UC…
- Bloody diarrhoea
- Colicky abdominal pains
- Tenesmus
- Constipation
- Rectal bleeding
- Systemic; malaise, fever, weight loss
- Extra-intestinal manifestations: erythema nodosum, episcleritis, uveitis, sacroilitis, PSC
Different categories of UC…
Mild disease= <4 stools per day
Moderate = <6 bloody stools per day
Severe = >6 bloody stools per day, with systemic upset (fever, HR>90, anaemia, raised CRP)
What is the diagnostic investigation for UC?
Flexible sigmoidoscopy with at least 2 biopsies from 5 different sites
What is a marker of IBD
Faecal calprotectin
Management of UC flare up…
A-E assessment and stabilisation
Bloods - inflammatory markers and electrolytes
Abdominal X-ray to rule out toxic megacolon
Induction of remission:
>Localised disease e.g. proctitis - topical 5-ASA e.g. mesalazine can be used
>Extensive disease - oral 5-ASA
>Moderate to severe disease - IV corticosteroids, with biological agents e.g. infliximab
*Surgery can be a curative option e.g. proctocolectomy and loop ileostomy
Management of stable UC…
- Oral 5-ASA
- Immunosuppressants such as azathioprine can be used
Pathophysiology of coeliac disease…
- T-cell mediated inflammation of the bowel due to antibody formation against TTG –> leads to enterocyte damage which results in malabsorption.
Presentation of coeliac disease…
- Malaise
- Prolonged fatigue
- Diarrhoea
- Bloating
- Abdominal discomfort
- Weight loss
- Anaemia
- Recurrent ulcers
What other conditions are associated with coeliac disease?
Dermatitis herpetiformis
Autoimmune thyroid disease
IBS
T1DM
What investigations are used for coeliac disease?
Blood tests: -FBC (iron and folate deficiency) -Biochem (low albumin, calcium, phosphate, B12 ) -LFTs (transaminases raised) -Coeliac antibodies (EMA, IgA TTG) Imaging: -Endoscopy and duodenal biopsy
What are the histological findings in coeliac disease?
- Villous Atrophy
- Intraepithelial lymphocytosis
- Crypt hyperplasia
What is the management of coeliac disease?
- Gluten free diet - needs to consult with dietician to advise on dietary changes required
- Diet can be supplemented with fibre, folic acid, iron, calcium and Vit D
