On Call: Diarrhea

Causes of Acute Diarrhea

Definitions

  • Diarrhea: ≥ 3 Loose/Watery Bowel Movements per Day
  • Invasive Diarrhea (Dysentery): Diarrhea with Blood or Mucous
  • Duration:
    • Acute: ≤ 14 Days (The Focus of This Review)
    • Persistent: 15-29 Days
    • Chronic: ≥ 30 Days

Nonoperative Causes

  • Infectious
    • Viruses
      • Norovirus
      • Rotavirus
      • Adenovirus
    • Bacteria
      • Clostridioides difficile
      • Salmonella
      • Shigella
      • Escherichia coli
      • Campylobacter
    • Parasites
      • Giardia
      • Cryptosporidium
      • Entamoeba
  • Food Intolerance:
    • Celiac Disease (Gluten Intolerance)
    • Lactose Intolerance
  • Use of Artificial Sweeteners
  • Underlying Bowel Disorder:
    • Inflammatory Bowel Disease (IBD)
      • Crohn’s Disease
      • Ulcerative Colitis
    • Small Intestine Bacterial Overgrowth (SIBO)
    • Irritable Bowel Syndrome (IBS)
  • Psychogenic Diarrhea
  • Radiation Therapy
  • Medications:
    • Promotility Medications/Laxatives
    • Antacids
    • Antibiotics

Postoperative Causes

  • Dumping Syndrome (Rapid Gastric Emptying)
  • Enzymatic Changes:
    • Loss of Pancreatic Enzymes (Pancreatectomy, etc.)
    • Increased Biliary Secretion – Acts as a Laxative (Cholecystectomy, Hepatobiliary Surgery, etc.)
  • Malabsorption/Malnutrition
    • Intestinal Resection
    • Bypass Procedures (Bariatric Surgery, etc.)
    • Entero-enteric Fistula
  • Ileocecal Valve Impairment (Ileocecectomy/Resection or Loss of Physiologic Control)
  • GI Bleeding – Blood Acts as a Cathartic Agent
  • Small Intestine Bacterial Overgrowth (SIBO)

Complications

  • Dehydration
  • Abdominal Pain, Bloating, & Cramping
  • Nausea & Vomiting
  • Loss of Electrolytes (Sodium, Potassium, Magnesium, & Chloride)
  • Non-Anion Gap Metabolic Acidosis

Management

General Evaluation

  • Physical Examination
  • Basic Labs (CBC, BMP)
  • Consider Clostridioides difficile (C diff) Stool Test if Indicated
  • Other Microbiologic Stool Test/Culture
    • Generally Unnecessary in Most Surgical Patients
    • Consider if Severe/Profuse or Associated with Concerning Signs (Blood, Mucous, or Fever)

General Management

  • Initial Management Consists of Fluid Resuscitation & Electrolyte Replacement Due to Excessive Losses
  • Consider Medical Treatments with Soluble Fiber & Antimotility Drugs
    • See Below
    • *Avoid Antimotility Medications in the Setting of Infectious Etiologies – Dangerous & Prevents Excretion of Pathogen
  • Specific Treatments May Be Indicated Based on Specific Cause
    • Dumping Syndrome (Rapid Gastric Emptying): Frequent Small Meals (High in Fiber/Protein, Low in Carbs/Sugar)
    • Pancreatic Enzyme Deficiency: Pancreatic Enzyme Replacement
    • Clostridioides difficile Colitis: Antibiotics
    • Other Infectious Etiology: Antibiotics/Antiviral as Indicated
  • Select Surgical Causes May Require Surgical Revision (Billroth II to Roux-en-Y, etc.)

Medical Treatment

  • First-Line: Soluble Fiber Supplement (Psyllium/Metamucil)
    • Absorbs Water to Slow Transit Time
    • *Avoid Insoluble Fiber Supplements (Wheat Bran) – Can Speed Up Transit Time
  • Second-Line: Antimotility Drugs
    • Loperamide (Imodium) – Generally Preferred First Medication (Lower Side Effects)
    • Diphenoxylate-Atropine (Lomotil)
    • Tincture of Opium
    • Codeine
  • Other Options:
    • Octreotide
    • Cholestyramine
    • PPI/H2-Blockers – Anti-Secretory
  • *See Pharmacology & Anesthesia: Antimotility (Antidiarrheal) Agents

Management of a High-Output Ostomy