65. Diarrhoea Flashcards
Causes of diarrhoea.
a) Children - acute
b) Children - chronic
c) Adults - acute
d) Adults - chronic
a) Gastroenteritis; systemic infection (UTI, otitis media, sepsis, HUS), food allergy,
b) Toddler’s diarrhoea (well child), IBS, chronic infection (eg giardia), IBD or coeliac, food intolerance (CMPA, lactose intolerance, etc.), systemic condition (CF, hyperthyroid)
c) Gastroenteritis; also drug causes (e.g. antibiotics); systemic illness (e.g. sepsis), surgical (e.g. appendicitis)
d) IBS, diverticular disease, IBD, colon Ca, coeliac, chronic infection, pancreatic disease, systemic (hyperthyroid), drugs, alcohol
Drugs that can cause diarrhoea
a) Antibiotics
b) Others
a) Most ABx (e.g. penicillins, cephalosporins, macrolides)
- About 25% are c.diff-related - main culprits: 4 Cs (co-amoxiclav, clindamycin, cephalosporins, ciprofloxacin)
b) Laxatives, prokinetics (e.g. metoclopramide), metformin (generally < 2/52), NSAIDs, PPIs, SSRIs, digoxin, colchicine, cytotoxics (e.g. methotrexate, chemotherapy), antacids, statins, theophylline, thyroxine
Investigations for diarrhoea.
a) Acute - when and how to investigate?
b) Chronic in children
c) Chronic in adults
a) Systemically unwell (e.g. fever), dehydration, persistent diarrhoea, recent hospitalisation/antibiotics, travel/ occupational risk of severe infection, low immunity.
- Do a stool sample for microbiology (if travellers - ova, cysts and parasites; if hospitalisation/ABx - c. diff testing)
b) - Stool sample: microbiology +/- ova, cysts and parasites, faecal calprotectin (if +ve - do colonoscopy)
- Sweat testing (CF), coeliac serology, serum eosinophils (may be raised in food allergies)
c) - Bedside: DRE, urine dip
- Bloods: FBC (anaemia, infection), haematinics (low iron, B12, folate, etc.), CRP/ESR (IBD, infection), LFTs (low albumin: protein-losing enteropathy), TFTs
- Coeliac serology
- Stool sample: faecal calprotectin, microbiology
- Lower GI endoscopy
- Other: eg. duodenal biopsy, USS/CT/barium studies, faecal elastase
Management of acute diarrhoea.
a) General measures
b) Specific treatments
c) Who to admit?
a) Rehydration and electrolyte replacement (Dioralyte), pain relief, good nutrition, hygiene measures, antidiarrhoeals (unless risk of toxic megacolon e.g. c diff, UC)
b) - Travellers/confirmed bacterial: ciprofloxacin 500 mg for 3/7 (or azithromycin if returning from South/SE Asia)
- C. diff: metronidazole (+ vancomycin if severe)
c) Systemically very unwell
- severely dehydrated
- unable to tolerate oral intake /severe vomiting
- risk of complications (e.g. low immunity, elderly and poor independence, taking steroids)
- peritonism, severe pain (possible appendicitis)
Red flag symptoms in diarrhoea.
a) Children (acute vs chronic)
b) Adults (acute vs chronic)
a) - Acute - Unwell, abdo pain, peritonism (appendicitis, intussusception), shock, pallor, jaundice, poor urinary output, bilious vomiting (volvulus), blood in stool (bacterial infection, intussusception or HUS -VTEC O157)
- Chronic - FTT, weight loss, abdo pain, systemic upset
b) Acute - Blood in the stool. Persistent vomiting. Nocturnal symptoms disturbing sleep. Painless, watery, high-volume diarrhoea - increased risk of dehydration.
Recent hospital treatment or antibiotic treatment.
- Chronic - weight loss, PR bleed, anaemia, abdominal or rectal mass, alternating constipation, FHx bowel or ovarian Ca
Assessing for dehydration.
a) mild
b) moderate
c) severe
a) Mild dehydration: thirsty, anorexia, nausea, light-headedness, postural hypotension; usually no signs.
b) Moderate dehydration: apathy, tiredness, dizziness, muscle cramps, dry mucous membranes, sunken eyes, reduced skin turgor, postural hypotension, tachycardia, oliguria.
c) Severe dehydration: weakness, confusion, reduced GCS, shock, tachycardia, marked peripheral vasoconstriction, systolic BP < 90, oliguria or anuria.
C. diff infection
a) Risk factors
b) Clinical features - 4 stages
c) Investigations
d) Management
a) Prolonged courses of ABx/ multiple ABx, old age, severe comorbidities, immunocompromised, invasive gastrointestinal procedures (endoscopy, NG tubes), long hospital stay, in long-term care, on ITU
b) - Usually presents 3 - 9 days post-ABx
- Asymptomatic; mild diarrhoea (self-limiting), pseudomembranous colitis, fulminant colitis and toxic megacolon
- Symptoms - watery diarrhoea, may be blood-stained, abdominal cramps, fever, septic features
c) - Bloods: FBC (raised WCC), CRP, UEs/creatinine
- Stool sample: stool cytotoxin test (gold standard) or culture for c. diff
- Imaging: erect CXR, CT/barium studies (dilatation, toxic megacolon)
- Sigmoidoscopy - may show pseudomembranous colitis (may take biopsy)
d) - Notify PHE
- Handwashing (soap and water) and patient isolation
- Replace fluid and electrolyte losses, and monitor
- Remove/change any identifiable antibiotic cause
- Treatment: mild-mod (oral metronidazole), severe (oral vancomycin)
Malabsorption.
a) Clinical features
b) If B12 and folate deficiency - why should cobalamin injection always precede folate supplementation?
a) Diarrhoea; steatorrhoea (pale, foul-smelling stool, float and difficult to flush); weight loss, vitamin and protein deficiencies (low iron, B12, folate, vit D, albumin, vitamin K - bleeding)
b) Risk of precipitating subacute combined degeneration of the cord
Gastroenteritis.
a) Causes
b) Presentation
c) Investigations
d) Management
e) When is it notifiable?
a) Viral (norovirus, rotavirus), bacterial (camp, e.coli 0157, salmonella, shigella, staph aureus), parasitic (entamoeba, giardia)
b) N/V, cramping pain, diarrhoea
More severe: Bloody diarrhoea (dysentery), fever, tachy
c) - Stool sample: c. diff toxin/ norovirus PCR, culture, ova, cysts and parasites
d) - Admit to hospital if very dehydrated/shocked, severe vomiting/unable to take oral fluids or at-risk of complications (eg. immunosuppressed)
- Hydration (fluids + ORS)
- Monitor electrolytes
- Loperamide (not if fever/dysentery - risk of toxic megacolon)
- If dysentery - oral ciprofloxacin
e) Food poisoning, dysentery
Travellers’ diarrhoea.
a) Particular risk factors
b) Definition/ presentation
c) Prevention
d) Management
a) - Area of travel: South/SE Asia, Central/South America, Africa
- Nature of trip: cruise, backpacking, resorts
b) - Increase in bowel movements to 3+/day during a trip abroad, usually to a less developed region
- Generally in first week or two of travel, and usually lasts less than 72 hours
c) - Antimotility drug - only if very severe or in need of long duration without motion (eg. long coach journey)
- Only take for 2 days maximum
d) - Usually self-limiting: ORS + safety net + infection control
- If dysentery/feverish - consider ciprofloxacin 500 mg bd for three days / azithro if from South/SE Asia
- If systemically very unwell, consider admission
Toddler’s diarrhoea.
a) What is it?
b) Management
a) Diarrhoea in children aged 1 - 5, with no other abnormalities; cause unknown but risk increased with low-fat diet and high amounts of sugary drinks
b) - Reassure
- Ensure good amount of fat (diet of pre-school children should have around 30-40% fat): eg. whole milk, yoghurts, etc.
- Reduce fruit juices, squash, sugary and fizzy drinks
- Ensure appropriate amount of fibre (not too high or
too low)
