Abdominal Conditions

According to the Centers for Disease Control and Prevention (CDC), the pediatric population in the United States accounts for 1.5 million outpatient visits and 200,000 hospitalizations per year for abdominal pain. The differential diagnosis for abdominal pain is vast, spanning from typically benign entities (e.g., constipation) to surgical emergencies (e.g., appendicitis and ovarian torsion). The most common complaints seen in pediatric urgent care involve acute vomiting and diarrhea. Therefore, this rotation guide focuses on the following:

• Gastroenteritis, Gastritis, and Enteritis

• Foodborne Illness

• Dehydration

Other abdominal complaints common in the urgent care setting are covered in the following rotation guides:

• Constipation, Upper and Lower Gastrointestinal Bleeding (Pediatric Gastroenterology)

• Abdominopelvic Emergencies (Pediatric Emergency Medicine)

Gastroenteritis, Gastritis, and Enteritis

Gastroenteritis is inflammation of the stomach and intestines, gastritis affects the stomach only, and enteritis is inflammation of the lining of the intestine. These conditions manifest with diarrhea or vomiting or both. Symptoms may be accompanied by fever, abdominal cramps, or both. The etiology is most often viral but can be bacterial (e.g., foodborne pathogens).

Diarrhea is defined as at least three loose or watery stools per day, or more-frequent passage of stool than is normal for the child. Diarrhea can be classified into the following three categories:

• acute diarrhea that lasts up to a few days

• acute bloody diarrhea

• persistent diarrhea (watery diarrhea lasting more than 2 weeks)

Evaluation

In most cases, the history and physical examination are enough to make a diagnosis and additional testing is not required.

History: Key information to obtain in the history includes:

• illness severity (quantify vomiting and diarrhea, fluid intake, and urine output)

• presence of blood in emesis or diarrhea

• presence of bile in emesis

• isolated vomiting (should prompt a broader differential diagnosis, including bacterial infection, diabetic ketoacidosis, abdominal mass, intestinal obstruction or foreign body, or increased intracranial pressure)

• rotavirus and hepatitis A immunization status

• travel history (to expand the differential of organisms that can cause gastroenteritis)

• known ill contacts and local patterns of illness (e.g., norovirus or salmonella outbreaks)

Physical exam: Physical evaluation should include the following assessments:

• hydration status, including vital signs, mucous membranes, tear production, pulses, capillary refill, skin turgor

• abdominal tenderness and peritoneal signs (may be indicative of a surgical issue)

• testicular exam (in boys) to evaluate for testicular pain, swelling, presence of cremasteric reflex

• signs of lower pelvic pain (in girls) could represent ovarian pathology (e.g., torsion)

• inspection of the anus for tears or fissures suggestive of inflammatory bowel disease

Workup

Laboratory evaluation is not necessary for most cases of viral gastroenteritis associated with mild-to-moderate dehydration.

• Stool culture is indicated if diarrhea is severe, prolonged, bloody, or associated with fever, or if there is concern for an outbreak due to a bacterial cause. Stool culture should be evaluated for Salmonella, Shigella, Campylobacter, Yersinia, Clostridioides difficile, and Shiga toxin-producing Escherichia coli. Similarly, stool can be tested for difficile toxins and ova and parasites. Viral etiology can be determined using reverse-transcriptase-polymerase-chain-reaction (RT-PCR) testing.

• In patients requiring intravenous (IV) hydration, serum electrolytes and glucose tests may be indicated.

Red flags that may indicate the need to broaden the differential diagnosis beyond viral gastroenteritis and require further workup include:

• fever associated with vomiting or diarrhea

• bloody diarrhea

• bloody or bilious emesis

• changes of mental status or toxic appearance

• clinical signs of severe dehydration (see table below)

• severe abdominal pain or surgical abdomen

Treatment

Treatment requires restoration and maintenance of hydration. Oral rehydration is the ideal method to rehydrate a patient with mild-to-moderate dehydration. If a patient has persistent vomiting, ondansetron (a selective serotonergic antagonist) may be prescribed as an antiemetic. If a patient continues to be unable to maintain oral hydration, IV fluids may be indicated. Patients with intractable emesis, oral rehydration intolerance or refusal, severe dehydration, or electrolyte abnormalities may require admission for closer observation. (See more on dehydration below.)

Foodborne Illness

The CDC estimates that one in six Americans become ill from a foodborne illness each year. The most common causes are viruses (e.g., norovirus). Foodborne illnesses can also be caused by bacteria, including Salmonella, Clostridium perfringens, Staphylococcus aureus, Clostridium botulinum, Escherichia coli, Campylobacter, Vibrio, and Listeria. Presentation is similar to viral gastroenteritis and can also be associated with fever, bloody diarrhea, cramping, headache, dehydration, and arthralgias, depending on the cause.

Workup

Laboratory testing is not recommended in most cases of presumed foodborne enteritis.

• If a clinician cannot determine the etiology of enteritis, then the recommendation for evaluation of a bloodborne infection or severity of dehydration is based on how clinically ill the patient appears.

• Stool testing should be performed if there is concern for an outbreak, and certain organisms should be reported to the CDC per state requirements.

• Most cases of foodborne gastroenteritis/enteritis do not require antibiotics because they usually self-resolve. Also, antibiotics may worsen the outcome for some infections, including Shiga toxin-producing coliand nontyphoidal Salmonella.

• Empiric antibiotics can be considered in patients with severe disease (prolonged or copious diarrhea) or gross hematochezia, or in patients who are immunocompromised or require hospitalization. If antibiotics are prescribed, stool testing should also be performed to confirm etiology and susceptibility testing.

Dehydration

Dehydration is a major concern in gastroenteritis as well as in other pediatric illnesses. Assessing dehydration status is an important skill in pediatric urgent care because it helps determine treatment and patient disposition.

Classification by severity: Dehydration can be classified into three groups according to severity:

• minimal or no dehydration (<3% fluid deficit)

• mild-to-moderate dehydration (3%−9% fluid deficit)

• severe dehydration (>9% fluid deficit or signs of shock)

Clinical signs and symptoms associated with severity of dehydration are summarized in the following table. Comparison to a recent weight (if available) can also help to assess severity of dehydration.

Rehydration can be achieved via oral, nasogastric, or intravenous routes.

• Mild-to-moderate dehydration:The oral route is preferred in patients with mild-to-moderate dehydration, if tolerated. Although oral solutions may be made at home, to prevent errors, it is recommended to utilize standard commercial oral rehydration solutions (e.g., Pedialyte, Enfalyte), especially in infants. While drinks with elevated sugar content are not usually recommended due to concern for osmotic diarrhea, a recent study showed that dilute apple juice followed by preferred fluids can be an appropriate alternative to electrolyte solutions in mild gastroenteritis with minimal dehydration. Parents should be instructed to give fluids slowly and steadily, starting with 5 mL every 5 minutes, and gradually increasing as tolerated. Once oral solutions are tolerated, soft and bland foods may be started.

• Severe dehydration: Patients with severe dehydration should receive rapid intravenous or intraosseous fluids with isotonic crystalloid solution (e.g., lactated Ringer solution or 0.9% sodium chloride solution).