What should an otherwise healthy adult do if they are vomiting thin yellow fluid?

Management of Vomiting Thin Yellow Fluid in Otherwise Healthy Adults

If you are an otherwise healthy adult vomiting thin yellow fluid (likely bile), focus immediately on oral rehydration with preferred beverages like water, tea, or diluted juice, and seek medical attention if symptoms persist beyond 48 hours, you develop severe dehydration signs, or vomiting becomes persistent. 1, 2

Immediate Assessment and Red Flags

First, assess for warning signs requiring urgent medical evaluation:

• Persistent vomiting (inability to keep fluids down for >12-24 hours) 3, 4
• Signs of severe dehydration: confusion, non-fluent speech, extremity weakness, dry mucous membranes, dry/furrowed tongue, sunken eyes (≥4 of these signs indicates moderate-to-severe volume depletion) 3
• Postural symptoms: severe dizziness when standing or pulse increase ≥30 beats/minute from lying to standing 3
• Bilious vomiting with abdominal pain (may indicate obstruction) 5, 6
• Blood in vomit 6, 4
• High fever (>38.5°C), altered mental status, or severe abdominal distension 2, 6

If any of these are present, seek immediate medical attention. 2, 6

Rehydration Strategy

For mild vomiting without severe dehydration:

• Drink preferred beverages including water, hot or iced tea, coffee, fruit juice, or even carbonated beverages 1
• Avoid formal oral rehydration solutions (ORS) unless you also have diarrhea—these are designed for electrolyte replacement in diarrheal illness, not simple vomiting 1
• Target fluid intake of ≥1.5 L/day, adjusting upward if vomiting continues 3
• Take small, frequent sips rather than large volumes at once 3

Important distinction: The yellow fluid you're vomiting is likely bile, which can occur with an empty stomach or persistent vomiting. This alone doesn't require ORS unless accompanied by diarrhea causing electrolyte losses. 1, 2

Symptomatic Management

Dietary modifications:

• Stop eating temporarily if vomiting is active, then resume small amounts of bland foods as tolerated 3, 2
• Eat slowly with meal duration ≥15 minutes when you resume eating 3
• Separate liquids from solids: avoid drinking 15 minutes before and 30 minutes after meals 3
• Small, light meals avoiding fatty, heavy, or spicy foods 2

Antiemetic consideration:

• Ondansetron (5-HT3 antagonist) is the most commonly recommended antiemetic for adults, though it can cause constipation 3, 6
• Over-the-counter options are reasonable for mild, self-limited vomiting 4
• Avoid long-term use of older antiemetics like metoclopramide or domperidone due to side effects 3

When to Seek Medical Attention

Contact a healthcare provider if: 2, 6, 4

• No improvement within 48 hours 2
• Unable to keep any fluids down for >12-24 hours 3, 4
• Development of dehydration signs (decreased urination, extreme thirst, dizziness) 3
• Persistent vomiting requiring thiamin supplementation consideration 3
• Worsening symptoms or new concerning features 2, 4

Common Pitfalls to Avoid

• Don't confuse dehydration types: Simple vomiting without diarrhea requires regular preferred beverages, not electrolyte solutions 1
• Don't force large volumes of fluid when actively vomiting—this often worsens symptoms 3
• Don't ignore persistent vomiting: Beyond 48 hours warrants medical evaluation to rule out underlying causes 2, 4
• Monitor for volume depletion: If you develop ≥4 signs (confusion, dry mouth/tongue, sunken eyes, weakness), you need medical assessment for possible IV fluid therapy 3

If vomiting persists or you cannot maintain hydration, intravenous isotonic fluids may be necessary, which requires medical facility evaluation. 3