Compare conditions

Put any two — or three — conditions side by side, adult or pediatric, to spot the look-alike differences fast, row by row.

Gastroenteritis and Dehydration

—

In one line

·A germ (virus or bacteria) inflames the gut, causing vomiting and diarrhea that pour water and salt out of the body—dehydration is the real danger.

—

Normal physiology

·The small and large intestines absorb water, salt, and nutrients from food while their lining (the mucosa) makes a protective mucus layer and pumps out immune cells to trap and kill any germs that sneak in with food or water.

—

What goes wrong

·A virus, bacterium, or parasite invades the gut lining, triggering inflammation that damages the cells that absorb water and salt—so fluid pours into the intestines instead of being absorbed, and the inflamed gut squeezes hard to push the invader out, causing vomiting and watery diarrhea.

—

Hallmark signs

·Watery diarrhea (loose, runny poop)
·Vomiting (throwing up)
·Belly cramps or pain
·Dry mouth and lips
·Sunken eyes
·Decreased urination (less pee or no wet diapers)
·Slow capillary refill (skin color takes longer than 2 seconds to come back after you press it)
·Fever (body temperature above normal)

—

Red flags · escalate now

·Blood in the stool or black, tarry poop
·No tears when crying, no urine for 6-8 hours, or sunken soft spot on baby's head
·Extreme sleepiness, confusion, or the child is too weak to stand or drink
·Severe belly pain that does not go away or gets worse
·High fever (over 102°F or 39°C in infants under 3 months, or over 104°F or 40°C in older children)

—

Workup

·Serum electrolytes (sodium, potassium, chloride, bicarbonate)
·Blood urea nitrogen (BUN) and creatinine
·Stool culture and testing for Shiga toxin or EHEC
·Complete blood count (CBC) with peripheral smear if bloody diarrhea is present
·Urine specific gravity or urine osmolality
·Venous or capillary blood gas if the child looks very sick

—

Treatment

·Oral rehydration solution (ORS) — a precise mix of salt, sugar, and water that matches what the gut absorbs best
·Intravenous fluids (normal saline or lactated Ringer solution) if the child cannot drink, is vomiting everything, or has severe dehydration with shock
·Ondansetron (Zofran) — a medicine that blocks the vomiting signal in the brainstem
·Antibiotics (azithromycin for Shigella or Campylobacter, ceftriaxone for invasive Salmonella, metronidazole for C. difficile) — only when a dangerous bacteria is confirmed
·Zinc supplementation (10–20 mg daily for 10–14 days) in children under 5 in low-resource settings
·Probiotics (Lactobacillus GG or Saccharomyces boulardii) started early in the illness
·Frequent reassessment of hydration status — check mucous membranes, skin turgor, urine output, capillary refill, and mental status every 2–4 hours

—

NCLEX trap

·About 8 out of 10 kids with gastroenteritis have a virus—rotavirus, norovirus, or adenovirus. Antibiotics kill bacteria, not viruses, so they do no good here. Save antibiotics for real signs of an invasive bacterial infection: bloody diarrhea, fever above 102°F (38.9°C) for more than 2 days, or severe belly pain that won't quit. Using antibiotics when you don't need them wipes out the good bacteria in the gut and lets Clostridioides difficile (C. diff—a dangerous germ) take over and cause an even worse infection.
·Diarrhea is the body's way of flushing the virus or bacteria out of the intestines (the long tubes that digest food). Stopping it traps the germ inside, which can make the infection worse and can cause toxic megacolon—the colon (the last part of the gut) swells up dangerously and can burst. Never give loperamide to kids under 12 or to anyone with bloody diarrhea. Let the body clear it out on its own.
·In gastroenteritis, dehydration (losing too much water from the body) is what can kill, not the vomiting itself. Start oral rehydration solution (ORS—like Pedialyte) right away in tiny, frequent sips: one teaspoon every 1 to 2 minutes. The special mix of salt and sugar in ORS helps the intestines soak up water even when the stomach is upset. Waiting makes dehydration worse and more dangerous.
·Plain water has no salt, and juice has too much sugar and no salt. Without the right balance, the intestines cannot absorb the water—it just passes through as more diarrhea. Use WHO oral rehydration solution (ORS). It has the exact ratio of sodium (salt), glucose (sugar), and water the gut needs to pull fluid back into the blood. Give small sips, not big gulps, because big gulps trigger more vomiting.
·Making less pee than normal is an early warning that dehydration is already happening. The kidneys (the two bean-shaped organs that filter blood and make pee) are holding onto water because the body is running low. If the child hasn't peed in 4 to 6 hours, or if the pee is dark and tiny in amount, that means the gut can't absorb fluids fast enough and you need to give IV fluids (fluids through a vein) now. Don't wait for the child to get sicker.
·Enterohemorrhagic E. coli—EHEC—makes a poison called Shiga toxin. That toxin can cause destroying red blood cells (hemolytic) uremic syndrome (HUS—the toxin destroys red blood cells and shuts down the kidneys). Giving antibiotics to EHEC makes the bacteria release MORE toxin and raises the risk of HUS. Never give antibiotics for bloody diarrhea until you know it isn't EHEC. Instead, watch the urine output (how much pee the child makes) and the creatinine (a blood test that shows how well the kidneys are working) closely.

—

Install Maldek by Hill as an app — studies work even offline