Projectile Vomiting: Causes and When to Worry

What makes vomiting projectile

Normal vomiting involves the stomach and abdominal muscles squeezing while the upper stomach relaxes. In projectile vomiting the force is much stronger, usually because:

• something blocks the stomach outlet or bowel, so the stomach contracts hard against resistance
• pressure in the skull is raised, directly stimulating the vomiting center in the brain, often without much nausea beforehand
• the stomach is overfilled, as in overfeeding or a large meal during a stomach bug

Projectile vomiting in babies

Pyloric stenosis

In pyloric stenosis, the muscle at the stomach outlet (the pylorus) thickens so milk cannot pass into the bowel. Key features:

• starts at 2 to 8 weeks of age, most often around 3 to 5 weeks
• forceful vomiting soon after feeds, becoming more frequent
• vomit is milk or curdled milk, not green
• the baby is hungry right after vomiting and wants to feed again
• fewer and smaller stools and wet diapers, weight loss
• more common in boys, especially firstborn boys, and with a family history

A doctor may feel a small olive-shaped lump in the upper belly and see waves moving across the stomach after a feed. Ultrasound confirms it. Treatment is a quick operation (pyloromyotomy) after fluids and salts are corrected. Babies usually feed normally within a day or two.

Other causes in babies

See vomiting in infants for more.

Projectile vomiting in children and adults

Stomach bugs and food poisoning

Viral gastroenteritis, especially norovirus, often begins with sudden forceful vomiting, followed by diarrhea, cramps and sometimes a low fever. Food poisoning from toxins (such as Staphylococcus aureus or Bacillus cereus) causes violent vomiting within 1 to 6 hours of eating. Both usually settle within 1 to 3 days.

Bowel obstruction

A bowel obstruction from adhesions after surgery, a hernia, a tumor or twisting causes cramping pain, a swollen belly, no passage of stool or gas, and vomiting that may become green or foul-smelling. This needs emergency care. In young children, intussusception is a key cause.

Raised pressure inside the skull

Head injury, bleeding, brain tumors, hydrocephalus and meningitis can cause projectile vomiting, often in the morning, with headache, drowsiness, blurred vision or confusion. See increased intracranial pressure.

Other causes

• Cyclic vomiting syndrome: repeated bouts of intense vomiting lasting hours to days, with normal health in between; linked to migraine and, in cannabis users, cannabinoid hyperemesis syndrome.
• Migraine, especially in children.
• Gastric outlet obstruction in adults from peptic ulcer scarring or cancer: vomiting of undigested food hours after meals.
• Severe motion sickness or overeating.

Dehydration: what to watch for

Home care

For children and adults with a stomach bug:

1. Rest the stomach for 30 to 60 minutes after vomiting.
2. Give small sips of oral rehydration solution: about 5 ml (1 teaspoon) every 1 to 2 minutes for a child, gradually increasing. Sports drinks and juice are less ideal because of their sugar content.
3. Keep breastfeeding babies, offering shorter, more frequent feeds.
4. Return to bland food when vomiting stops: toast, crackers, rice, bananas.
5. Wash hands thoroughly with soap and water. Alcohol gel does not reliably kill norovirus.

Anti-nausea medicines (such as ondansetron) are prescribed in some cases, especially for children at risk of dehydration. Avoid over-the-counter anti-nausea medicines in young children unless a doctor advises them. Do not give bismuth subsalicylate (which contains a salicylate) to children or teenagers.

How doctors find the cause

Doctors ask about the age, timing relative to meals, color of the vomit, stools, fever, pain, head injury and weight. Examination looks at hydration, the abdomen and neurological signs. Tests may include blood tests for salts and kidney function, an abdominal ultrasound (for pyloric stenosis or intussusception), X-rays or CT for obstruction, and brain imaging when pressure inside the skull is suspected.

Frequently asked questions

Is projectile vomiting in a baby serious?

One episode after a big feed is often harmless. Repeated projectile vomiting in a baby aged 2 to 8 weeks, especially if the baby seems hungry right afterward, can mean pyloric stenosis and needs same-day assessment. Green vomit is always an emergency.

What causes projectile vomiting in adults?

Most often a stomach bug such as norovirus or food poisoning. Less common causes include bowel obstruction, a stomach outlet blockage from an ulcer, cyclic vomiting syndrome and, rarely, raised pressure inside the skull from head injury, bleeding or a tumor.

What should I do after my child projectile vomits?

Wait 30 to 60 minutes, then give small, frequent sips of oral rehydration solution. Watch for signs of dehydration such as fewer wet diapers or no tears. Seek urgent care if vomit is green or bloody, your child is very sleepy, or vomiting continues.

Can projectile vomiting happen without a fever?

Yes. Pyloric stenosis, bowel obstruction, overfeeding, food poisoning from toxins and raised pressure inside the skull often cause projectile vomiting without fever. The absence of fever does not rule out a serious cause.

How is pyloric stenosis treated?

After correcting dehydration and salt levels with IV fluids, surgeons perform a pyloromyotomy, cutting the thickened muscle so food can pass. It is often done by keyhole surgery. Most babies feed normally within a day or two and have no long-term problems.