What is the assessment and treatment plan for a patient presenting with diarrhea?

Assessment and Plan for Diarrhea

Initial Assessment

Assess hydration status immediately using clinical signs: skin turgor, mucous membrane moisture, capillary refill time, orthostatic vital signs, and mental status to classify dehydration severity as mild (3-5% deficit), moderate (6-9% deficit), or severe (≥10% deficit). 1, 2

Key History Elements

• Duration and frequency: Determine if acute (<1 month) or chronic (≥1 month), number of stools per day, and stool consistency using Bristol Stool Form Scale 2, 3, 4
• Stool characteristics: Presence of blood, mucus, or nocturnal symptoms 1, 2
• Red flag symptoms: Fever, severe abdominal pain, dizziness upon standing, signs of sepsis, or immunocompromised status 2, 3, 5
• Medication review: Identify diarrheogenic agents, recent antibiotics, or drugs that prolong QT interval 1, 6
• Dietary exposures: Recent travel, foodborne illness risk, lactose-containing products, alcohol, high-osmolar supplements 1, 2

Physical Examination Priorities

• Dehydration markers: Prolonged capillary refill (>2 seconds), cool/poorly perfused extremities, prolonged skin tenting, dry mucous membranes 1
• Severe dehydration signs: Altered mental status, severe lethargy, rapid deep breathing (acidosis), decreased perfusion 1
• Abdominal examination: Rule out distention, peritoneal signs, or palpable masses 5

Diagnostic Testing Indications

Reserve laboratory workup for patients with bloody stools, persistent fever, severe dehydration, immunocompromised status, symptoms >7 days, or suspected nosocomial infection. 2, 3, 5

When to Order Tests

• Stool studies: Culture for bacterial pathogens, C. difficile testing, fecal leukocytes for bloody diarrhea, fever, or leukocytosis >15,000 cells/mm³ 1, 2, 3
• Blood work: Complete blood count and electrolyte profile for grade 3-4 diarrhea or signs of severe dehydration 1, 3
• Avoid routine testing: Most acute watery diarrhea cases are self-limited viral gastroenteritis requiring no diagnostic workup 3, 7, 8

Rehydration Strategy

Initiate oral rehydration therapy (ORT) with reduced osmolarity solution containing 50-90 mEq/L sodium as first-line treatment for all patients with mild to moderate dehydration. 1, 2, 3

Rehydration Protocol by Severity

Mild dehydration (3-5% deficit):

• Administer 50 mL/kg ORS over 2-4 hours using small volumes initially (one teaspoon), gradually increasing as tolerated 1
• Reassess hydration status after 2-4 hours; if still dehydrated, reestimate deficit and restart 1

Moderate dehydration (6-9% deficit):

• Administer 100 mL/kg ORS over 2-4 hours using same gradual approach 1

Severe dehydration (≥10% deficit, shock):

• This is a medical emergency requiring immediate IV rehydration 1
• Administer 20 mL/kg boluses of Ringer's lactate or normal saline until pulse, perfusion, and mental status normalize 1
• May require two IV lines or alternate access (venous cutdown, femoral vein, intraosseous) 1
• Transition to oral intake once consciousness returns 1

No dehydration:

• Skip rehydration phase and proceed directly to maintenance therapy 1

Ongoing Loss Replacement

• Replace measured losses: 1 mL ORS per gram of diarrheal stool 1
• Approximate replacement: 10 mL/kg per watery stool, 2 mL/kg per emesis episode 1

Dietary Management

Immediately eliminate all lactose-containing products, alcohol, and high-osmolar supplements; initiate BRAT diet (bananas, rice, applesauce, toast, plain pasta) with frequent small meals. 1, 2

Specific Dietary Instructions

• Drink 8-10 large glasses of clear liquids daily (Gatorade, broth) 1, 2
• Breast-fed infants: Continue nursing on demand 1
• Bottle-fed infants: Use full-strength lactose-free or lactose-reduced formulas immediately upon rehydration 1
• Gradually reintroduce solid foods as diarrhea resolves 1

Lactose Intolerance Monitoring

• True lactose intolerance indicated by worsening diarrhea upon reintroduction of lactose-containing foods, not by stool pH <6.0 or reducing substances >0.5% alone 1

Pharmacological Management

Antimotility Agents

Loperamide may be initiated for uncomplicated watery diarrhea in immunocompetent adults at 4 mg initial dose followed by 2 mg after each unformed stool (maximum 16 mg/day), but is CONTRAINDICATED in children <2 years, bloody diarrhea, fever, or suspected infectious colitis. 3, 6, 7

Critical Loperamide Warnings

• Cardiac risks: QT prolongation, Torsades de Pointes, ventricular arrhythmias, cardiac arrest, and sudden death reported with higher-than-recommended doses 6
• Avoid in combination with: QT-prolonging drugs (Class IA/III antiarrhythmics, antipsychotics, moxifloxacin, methadone), CYP3A4 inhibitors (itraconazole), CYP2C8 inhibitors (gemfibrozil), P-glycoprotein inhibitors (quinidine, ritonavir) 6
• High-risk patients: Elderly, congenital long QT syndrome, cardiac arrhythmias, electrolyte abnormalities, hepatic impairment 6
• Discontinue after: 12-hour diarrhea-free interval 1, 3
• Pediatric contraindication: Respiratory depression and cardiac toxicity risk in children <2 years 6

Octreotide for Severe Cases

• Consider for grade 3-4 diarrhea or persistent symptoms despite loperamide: 100-150 μg subcutaneously three times daily, escalating to 500 μg three times daily if needed 1, 3
• Administer IV (25-50 μg/hr) if severe dehydration present 1

Antiemetics

• Ondansetron may facilitate oral rehydration tolerance in children >4 years and adolescents with vomiting 3

Antibiotic Therapy

Avoid empiric antibiotics for routine acute watery diarrhea; reserve for specific pathogens (Shigella, Campylobacter, C. difficile), severe inflammatory diarrhea in immunocompromised patients, or signs of sepsis. 3, 7, 8

When to Consider Antibiotics

• Bloody diarrhea with confirmed bacterial pathogen 3, 7
• Immunocompromised patients with persistent symptoms 2, 3
• Severe inflammatory diarrhea with fever and systemic toxicity 1, 3
• Fluoroquinolone is typical empiric choice when indicated 1

Hospitalization Criteria

Admit patients with severe dehydration (≥10% deficit), hemodynamic instability, signs of sepsis, leukocytosis >30,000 cells/mm³, inability to tolerate oral fluids, or grade 3-4 diarrhea with fever/neutropenia/blood in stool. 1, 2, 3

Alternative to Hospitalization

• Select patients may be managed with intensive home nursing or day hospital care if no sepsis, fever, or neutropenia present 1

Monitoring and Follow-Up

Instruct patients to track daily stool number and consistency, and immediately report fever, blood in stool, severe abdominal pain, dizziness upon standing, or fainting episodes. 1, 2, 3

Reassessment Triggers

• No clinical improvement within 48 hours warrants discontinuation of current therapy and provider contact 6
• Development of abdominal distention, constipation, or ileus requires immediate loperamide discontinuation 6
• Fainting, rapid/irregular heartbeat, or unresponsiveness requires emergency evaluation 6

Special Population Considerations

Immunocompromised patients: Lower threshold for stool studies, blood cultures, and empiric antibiotics 2, 3

Pregnant women: Maintain aggressive hydration and avoid teratogenic medications 2

Elderly patients: Increased susceptibility to QT prolongation; avoid loperamide with QT-prolonging drugs 6

AIDS patients: Stop loperamide at earliest signs of abdominal distention due to toxic megacolon risk 6

Common Pitfalls to Avoid

• Never use antimotility agents in bloody or febrile diarrhea due to risk of toxic megacolon and prolonged pathogen shedding 3, 6
• Never exceed recommended loperamide dosing (16 mg/day maximum) due to cardiac toxicity risk 6
• Never delay IV rehydration in severe dehydration as this constitutes a medical emergency 1
• Never routinely order stool cultures for uncomplicated acute watery diarrhea 3, 7, 8
• Never withhold fluids and nutrition during diarrhea; early refeeding improves outcomes 1, 7