In Part 2 of this pediatric abdominal pain Episode – Pediatric Gastroenteritis, Constipation & Bowel Obstruction, Dr. Anna Jarvis, Canada’s “mother of pediatric emergency medicine” and Dr. Stephen Freedman, one of Canada’s pre-eminent researchers in pediatric GI emergencies, discuss the assessment, work-up and treatment of pediatric gastroenteritis, with particular attention to gastroenteritis & acute abdomen mimics, how best to assess hydration status, the nuances of the use of ondansetron and the prose and cons of various rehydration methods. A detailed discussion of the most common and lethal causes of acute abdomen bowel obstruction in pediatrics follows, including intussesception and midgut volvulus. Finally, the differential diagnosis and best management of the most common cause of pediatric abdominal pain, constipation, is reviewed.
Anna Jarvis and Stephen Freedman answer such questions as: Does Ondansetron mask serious illness? Should we be sending home children with scripts for Ondansetron? What are the contra-indications to Ondansetron? What is the role of anti-diarrhea medications like probiotics in the pediatrics? How good are we at clinically assessing hydration status in children? What is any easy way to remember oral rehydration doses? Which, if any, lab tests are indicated for children with gastroentritis and why? When should we suspect Hemolytic Uremic Syndrome in a child with diarrhea? What is the value of Abdominal X-rays in pediatrics? What are the clinical pearls that can help us diagnose intussusception in a timely manner before gut ischemia sets in? Which is better to diagnose intussusception – ultrasound or enema? In what situations can should children with intussusception go directly to surgery without a barium or air enema? What is the best medication for treatment of pediatric constipation? and many more Pediatric Gastorenteritis, Constipation & Bowel Obstruction pearls…….
Written summary and blog post written by Claire Heslop edited by Anton Helman January 2012
Cite this podcast as:Jarvis, A, Freedman, S, Helman, A. Part 2: Pediatric Gastroenteritis, Constipation and Bowel Obstruction. Emergency Medicine Cases. January, 2012. https://emergencymedicinecases.com/episode-19-part-2-pediatric-gastroenteritis-acute-constipation-bowel-obstruction/. Accessed [date].
Common diagnosis but may hide sinister pathology, so consider it a diagnosis of exclusion
In cases of isolated vomiting, especially if prolonged, consider alternate diagnoses: intracranial mass, meningitis, strep throat, pneumonia, myocarditis, appendicitis, UTI etc.
Sick contacts (siblings, day care, travel or relatives visiting from abroad), contact with farm‐products (eg, unpasteurized milk), unclean water exposure, prior episodes (if chronic or recurrent, might need out‐ patient work‐up r/o IBD), new animals or foods
Highly sensitive but non‐specific, with clinicians poor at differentiating the different degrees of severity and usually over‐estimating dehydration leading to over‐aggressive resuscitation
Only 3 findings have significant LR+: prolonged cap refill, abnormal skin turgor, tachypnea
1. NO OR MILD DEHYDRATION: None of the features below
2. SOME DEHYDRATION: Some components of ‐ unwell general appearance (eg, fussy, leathargic), mucous membranes dry, absence of tears, sunken eyes, prolonged capillary refill, abnormal skin turgor and tachypnea –PO rehydration indicated (safer than IV)
3. SEVERE DEHYDRATION: Most or all of the above features, with abnormal vital signs –IV or NG rehydration indicated
Majority of children do NOT need investigations, except for: accucheck if lethargy for hypoglycemia secondary to poor oral intake); to rule out other diagnoses ‐ urinalysis in polyuria/polydipsia for DKA or in children with fever and prior UTIs to rule out same
Electrolyte abnormalities are usually minor and rarely impact management, however if starting IV rehydration, then electrolytes are important to monitor to avoid iatrogenic electrolyte imbalances
Indications for stool cultures: travel to endemic countries, >10 diarrhea episodes in 24hrs, >5d duration and not resolving, blood and/or mucous in stools, and unremitting fever
Oral vs IV Rehydration: Compared with IV rehydration, oral rehydration therapy is associated with a lower risk of complications such as electrolyte imbalances, cerebral edema, phlebitis and cellulitis; therefore oral rehydration therapy is recommended as the treatment of choice for children with acute gastro who are in the category of ‘some’ dehydration
Pearls for oral rehydration with Pedialyte
Pedialyte dose: 5cc if 3yo q5mins, for a goal of around 30cc (1oz) per kg per hour for the first 3‐4hrs; Dr. Jarvis recommends starting slower during the first 30‐ 60min to minimize the chance of emesis
Continue to breastfeed at the same time, and add 10cc/kg/stool for diarrhea
Ondansetron (see Freedman, NEJM 2006 and Fedorowicz, Cochrane Review 2011)
Given as single dose (repeat if vomiting within 15min, and keep patient NPO for 15 minutes before starting pedialyte, as it takes that long to be effective); Dr. Freedman suggests no prescription for home
– no benefit shown and increases diarrhea, and if child suffers from worsening vomiting, he/she needs a formal reassessment
Do NOT use as a diagnostic tool (i.e. if a child stops vomiting with Ondansetron, it does NOT rule out alternate more sinister diagnoses such as appendicitis; use it therapeutically only)
Ondansetron may prolong QTc interval, so do not use in patients with known prolonged QTc, hypokalemia or hypomagnesemia, congenital heart disease or CHF as it may cause arrhythmias
Antibiotics are rarely required, even for bacterial gastro; consider antibiotics when child is persistently ill and is high‐risk (immunocompromised , sickle cell disease, or use of corticosteroids or chemotherapy), or risk factors for C.diff are present (neonates and graduates of NICU, IBD patients, or immunosuppressed recently on antibiotics)
Gastroenteritis Discharge instructions
Early introduction of solids in addition to fluids, with small frequent feeds limited in complex sugars (eg, fruit juices); diarrhea may increase initially, so give pedialyte in addition to food
Return to care if child has bloody stool, increasing pain or fever, is lethargic (“too sleepy”) or behaves unusually for him/her
Antidiarrheals: Do NOT use loperamide (may cause lethargy, paralytic ileus, case reports of death), and bismuth is not recommended by our experts, but probiotics may be used given their relative safety (except in children with central lines, congenital heart disease or short gut, as they lead to higher infection rates) and somewhat improved outcomes (1d less of diarrhea, but only in severe cases)
Prolapse of a segment of intestine into the lumen of an immediately adjacent part, and is the most common surgical emergency of the abdomen in children from 6mo to 6yo (peak at 18‐30mo)
Classic triad of intermittent crying, bloody stools and sausage‐shaped mass in the abdomen seen in <40% of cases
History for Intussusception
Crying is often severe and different than usual crying, with the child dropping into fetal or knee‐chest position, and behaving normally a few minutes later
2 presentations: either vomiting (sometimes due to pain, and bilious only if prolonged) ± abdominal pain in older children, or lethargy with paleness (especially in younger infants, where parents might describe the child’s condition as “all the life got sucked out of them”)
May elicit a history of recent viral illness, given that intussusception often requires a lead point such as enlarged lymph glands (eg, Peyer’s patch), Meckel’s diverticulum, or mesenteric duct remnant
Classic currant jelly stool (loose stool with mucous and blood) is a LATE finding and only present in 10% of cases
Physical for Intussesception
The necessity of performing a rectal exam cannot be overstated, as fecal occult blood will appear before gross blood (by which time it is “too late” given that there is likely already bowel ischemia)
May feel an “empty” RLQ or a sausage‐shaped mass in the RUQ just below the liver
Examination should focus on ruling out inguinal hernia, testicular torsion, midgut volvulus (80% present in first year of life, where bowel turns around ligament of Treitz and causes bilious vomiting), as well as child abuse, sepsis, meningitis, bacterial gastroenteritis, UTI (intermittent crying when the child urinates due to irritation)
Investigations and management for Intussusception
Used mainly to rule out other or concomitant diagnoses (bowel obstruction or perforated viscus), but may see subtle target sign in
RUQ (subtle just below last rib and to side of spine)
Lack of air in RLQ, or
Crescent sign in LUQ – only 23% of cases have these signs
Target sign of intussusception
Crescent sign of intussusception
Ultrasound in Intussusception
Diagnostic test of choice, with sensitivity 99%
Less painful than enema, which is, however, also therapeutic
Air or barium enema – center‐dependent; air may cause compartment syndrome in case of perforation due to high pressures, but barium may cause chemical peritonitis if it gets into the perineum
Direct to surgery in very young patients, prolonged symptoms (>15hrs), acidotic child, evidence of ongoing ischemia, gross blood per rectum getting worse, or hemodynamically unstable
Definition as per RomeIII criteria
≤2 stools per week for a duration of 2mo if patient >2yo and for duration of 4mo if patient <2yo, or with evidence of overflow incontinence (no stool, then diarrhea, then no stool, etc), or stools that clog toilet
Functional constipation is the most common cause of abdominal pain in children, but consider it a diagnosis of exclusion as severe underlying disease may be present
Differential diagnoses of Pediatric Constipation
Hirschprung’s disease: severe obstipation with overflow diarrhea and abdominal distention in non‐ thriving and cranky child, which may present with toxic megacolon
Cystic fibrosis and hypothyroidism: assess family history, and whether screening was performed
Others: Down syndrome, myelomeningocele or neuromuscular problems (slow to walk, walking “funny”), celiac disease (family history), child abuse
Oral medications work better when combined with enemas in the ER, but explain to the parents that it takes time to re‐train the bowel (sometimes years)
Enemas: if child <2yo, use saline enema 20cc/kg, and if child >20‐25kg, use adult fleet enema
High-Yield Associations and Pearls in Pediatric Abdominal Pain
Intermittent pain with change in stools (esp. bloody) ‐ intussusception
Bilious vomiting in neonate ‐ malrotation of the gut
Scrotal swelling or discoloration ‐ testicular torsion
Polyuria + Polydypsia ‐ DKA
Recent Mononucleosis ‐ spleen rupture
Petechial rash to buttocks and legs ‐ HSP
Hematuria + proteinuria ‐ HSP
Sterile pyuria ‐ appendicitis
Glucosuria and ketonuria ‐ DKA
Occult blood in stools ‐ intussusception or advanced volvulus
“Adult diagnoses” such as cholecystitis, renal colic, and incarcerated hernia can also all occur in children
Hemolytic Uremic Syndrome (HUS)
Triad of microangiopathic hemolytic anemia, thrombocytopenia and renal insufficiency caused by E.coli O157:H7, leading to bacterial enteritis
Clinical features: bloody stool and abdominal pain, lethargy, low‐grade fever, paleness and tachycardia due to anemia, petechiae, and tea‐colored urine due to blood, periorbital edema (esp. upon waking)
HUS Pearls: the haemolytic component may present after the diarrhea has resolved; do not give antibiotics on spec if you suspect HUS because it may worsen disease
Dr. Jarvis, Dr. Freedman, Dr. Helman and Dr. Heslop have no conflicts of interest to declare.
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4. Freedman SB, Adler M, Seshadri R, Powell EC. Oral ondansetron for gastroenteritis in a pediatric
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For more Pediatric EM learning visit trekk.ca – Translating Emergency Knowledge for Kids (TREKK) is a growing network of researchers, clinicians, health consumers and national organizations who want to accelerate the speed at which the latest knowledge in children’s emergency care is put into practice in general EDs – rural, remote or urban.
Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.