What causes loose orange stool, near syncope, nausea, and palpitations?

Acute Gastroenteritis with Autonomic Symptoms

This presentation of loose orange stools with near-syncope, nausea, and palpitations most likely represents acute gastroenteritis with significant dehydration causing orthostatic hypotension and compensatory tachycardia. 1

Immediate Assessment Priorities

Evaluate for severe dehydration and hemodynamic instability first, looking specifically for:

• Orthostatic vital signs (blood pressure drop >20 mmHg systolic or pulse increase >30 bpm when standing) 1
• Signs of hypovolemia: tachycardia, hypotension, dizziness, decreased skin turgor 2
• Fever above 38.5°C, which would suggest inflammatory or infectious diarrhea 1
• Evidence of peritonitis or acute abdomen (rigid abdomen, rebound tenderness) 2, 3

The near-fainting and palpitations are concerning autonomic symptoms that indicate significant volume depletion requiring urgent fluid resuscitation. 1

Understanding the Orange Color

The orange stool color is typically benign and related to:

• Dietary factors (carrots, sweet potatoes, foods with beta-carotene) 2
• Rapid transit time preventing normal bile pigment metabolism 2
• Certain medications or supplements

This color alone does not indicate serious pathology unless accompanied by blood, which would appear red or black. 2

Initial Management Algorithm

Step 1: Fluid Resuscitation

If signs of severe dehydration are present (orthostatic symptoms, tachycardia, hypotension), initiate intravenous fluid resuscitation immediately. 1 For mild to moderate dehydration without hemodynamic compromise, oral rehydration is first-line therapy. 1

Step 2: Symptom Control

• For nausea and vomiting, use antiemetics such as ondansetron or metoclopramide, though be cautious with ondansetron if there are cardiac risk factors or QT prolongation concerns 4, 5
• For uncomplicated diarrhea without fever or bloody stools, loperamide 4 mg initially, then 2 mg after each unformed stool (maximum 16 mg daily) 1

Critical caveat: Do NOT use loperamide if there is fever, bloody stools, or suspected inflammatory/infectious diarrhea, as this can worsen outcomes and mask complications. 1

Step 3: Dietary Modifications

• Eliminate lactose-containing products and high-osmolar supplements 1
• Avoid caffeine, alcohol, and spicy foods 1
• Resume age-appropriate diet immediately after rehydration 1

Step 4: Monitoring Instructions

Instruct the patient to watch for warning signs requiring immediate return:

• Fever above 38.5°C 1
• Bloody stools 1
• Persistent dizziness when standing 1
• Severe or worsening abdominal pain 1
• Inability to keep down fluids 1

When to Investigate Further

If symptoms persist beyond 48 hours despite treatment, obtain stool studies for infectious causes including bacterial pathogens and Clostridium difficile if there is recent antibiotic use. 2, 1

Consider imaging (CT abdomen/pelvis) if:

• Severe persistent abdominal pain develops 2
• Signs of obstruction appear (progressive distension, obstipation) 2, 3
• Peritoneal signs develop 3

Special Considerations

In elderly patients, be aware that fecal impaction can paradoxically present as loose stools with overflow diarrhea, which may explain alternating symptoms. 1 This population is also at higher risk for dehydration complications. 1

The combination of GI symptoms with autonomic features (near-syncope, palpitations) strongly suggests volume depletion rather than primary cardiac or neurologic pathology, but if symptoms persist after adequate rehydration, consider alternative diagnoses including cardiac arrhythmias, medication effects, or metabolic disturbances. 2, 6

Most cases of acute gastroenteritis are self-limiting and resolve within 7 days with supportive care. 2 The key is preventing complications through adequate hydration and recognizing warning signs that require escalation of care.