Diarrhoea

Overview

Diarrhoea is defined as increased volume or frequency of stool, generally of a more liquid consistency

• Three or more loose liquid stools per 24 hours, and/or
• Stools that are more frequent than what is normal for the individual, and/or
• Stool weight greater than 200g/dL

Has a number of causes. Most are idiopathic/viral. The most important first step in managing a patient with diarrhea is to assess the fluid status of the patient. Hypotensive patients should get a normal saline bolus. Infectious causes should always be ruled out in acute diarrhea

• When to admit a patient with diarrhea
  • Hypotension or orthostasis
  • Severe pain
  • Fever
  • Abdominal tenderness
• Outpatient treatment of diarrhea
  • Remind the patient the importance of adequate hydration
  • Gatorade, Pedialyte, and other isotonic drinks are preferable to water (but any hydration is better than none)
  • Basic food safety education
  • Return to the clinic if diarrhea has gone on for more than 2 weeks

Acute Diarrhea

Determine whether or not the diarrhea is bloody.

• Investigations
  • Stool studies
    • Stool lactoferrin (WBCs)
    • Stool RBCs
    • Ova and Parasites (O&P) or Giardia antigen
    • Culture
    • Stool PCR
    • C. diff toxin
    • Stool osmotic gap (normal btw 50-100 mOsm/kg)
    • Fecal fat
  • Complete Blood Count
  • BMP
  • Blood cultures

Infectious Bloody Diarrhea

Has a + stool lactoferrin. Most cases are self-limited. Note for ischemic bowel disease in older patients (Pain will be a prominent symptom, needs abdominal x-ray)

• Causes of bloody diarrhea
  • Salmonella (MCC: poultry, eggs, and milk)
  • Campylobacter (MCC: poultry, eggs, and milk; ass with Guillain-Barre syndrome, Reactive arthritis)
  • Shigella
  • Yersinia
  • Enterohemolytic Escherichia Coli (EHEC)
  • E. coli O157:H7 (Ass with HUS; never ever ever ever give antibiotics or platelets)
  • Entamoeba histolytica
  • Vibrio parahemolyticus (associated with shellfish consumption)
  • Vibrio vulnificus (associated with patients with liver disease or high iron state)
• Treatment if the patient is stable
  • Observation and fluid replacement
• Treatment if the symptoms are severe
  • PO Ciprofloxacin (or another fluoroquinolone) +/- Metronidazole
  • Doxycycline (If history points to V. vulnificus)
  • DO NOT use antibiotics in patients with HUS

Infectious Non-bloody diarrhea

Has a negative stool lactoferrin. Again, most cases are self-limiting

• Causes of non-bloody diarrhea
  • Viral (Rotavirus, Norovirus)
  • Giardia (associated with camping, consumption of (+O & p or + Giardia antigen) stream water, oral-anal sexual contact, severe bleeding )
  • Bacillus cereus (associated with reheated fried rice, vomiting + diarrhea)
  • Staphylococcus aureus (associated with dairy, coleslaw, picnics, vomiting + diarrhea; little mini outbreaks)
  • Clostridium perfringens (associated with meat that has been sitting out too long)
  • Listeria monocytogenes (deli foods, increased incidence in pregnancy)
  • Cryptosporidium (associated with HIV CD4 < 100, high ALP, acid fast +)
  • Isospora belli (associated with HIV CD4 < 100, high eosinophil, acid fast +)
• Treatment if the patient is stable
  • Observation and fluid replacement
• Treatment if symptoms are severe
  • PO Ciprofloxacin (or another fluoroquinolone) +/- Metronidazole
• Treatment of a pregnant woman with severe symptoms
  • IV Ampicillin
• Treatment if the patient has AIDS
  • HAART to get CD4 count up > 100
  • TMP-SMX if isospora belli
  • DO NOT use antibiotics in patients with HUS

Antibiotic-associated (Clostridiodes difficile)

Very common in hospitals. Due to overgrowth of C. difficile in large bowel. Any antibiotics can precipitate it but Clindamycin tends to be a common one.

• Patient history
  • Patient is on antibiotics and presents with diarrhea
• Investigations
  • C. difficile toxin: Positive
• Treatment
  • PO Metronidazole
• Treatment if symptoms abate and recur
  • Re-treat w/PO Metronidazole
• Treatment if symptoms do not abate after 2 days
  • PO Vanomycin
• Complications of C. diff
  • Toxic megacolon
  • Perforation

Lactose intolerance

Human breast milk contains lactose, which is normally digested into glucose and galactose by a brush border enzyme lactase. In most populations, lactase activity declines throughout childhood. Usually, lactase deficiency is asymptomatic. However, in some, it may cause colicky pain, abdominal distension, increased flatus, borborygmi, and diarrhea after ingesting milk or milk products.

• Primary lactase deficiency
  • Genetic
  • Jejunal morphology is normal
• Secondary lactase deficiency
  • Occurs due to a disease process that damages the jejunal mucosa eg. celiac disease, viral gastroenteritis
• Diagnosis
  • Clinical: Patient shows improvement after dietary lactose withdrawal.
  • Lactose hydrogen breath test
• Treatment
  • Dietary exclusion of lactose