Pediatrics Board Question / A 2 year-old present with a one day history of profuse watery diarrhea

Pediatrics Board Question / A 2 year-old present with a one day history of profuse watery diarrhea

Posted by Stuart C. Silverstein, MD Laughing Your Way to Passing the Pediatric Boards on Sep 27th 2023

A 2 year-old present with a one day history of profuse watery diarrhea

A 2-year-old presents with a one day history of profuse watery diarrhea, occasionally green in color, with no blood noted. Last night, he vomited twice and had a tactile temperature with mild abdominal pain. He has not been drinking and his diarrhea has made it hard to tell if he has had any urine output.

The parents deny any exposure to toxic substances and, except for a course of amoxicillin a month ago, he has taken no other medications and has not eaten any spoiled food. There are 3 children from his daycare who also have diarrhea. His past medical history is unremarkable.

On physical exam, you note the child to be listless with dry mucous membranes.

He is afebrile with HR 150, RR 25,

BP 85/60 Cap refill > 3 seconds with extremities cool to touch.

HEENT- TMs intact, no erythema

Throat – Clear

Lungs – Clear

Card – S1S2 No murmur

Neuro – Lethargic, symmetric tone,

with DTR 2+ throughout


WBC 11.5
Hgb 12 HCT 36.5 Segs 55%

Lymphs 40% Monocytes 5%
Platelets 220
LLC 31

Sodium 136 Potassium 4.5

Bicarb 14 BUN 32 Cre 0.5

UA (cath)

Sp Gravity 1.050 pH 5.2
Glucose negative Ketones

WBC- 2 RBC – 2

Bacteria – negative

Summary of  this Pediatrics Board like question is as follows 

You are presented with a 2 year old with watery diarrhea and vomiting the previous night with tactile fever. The diarrhea is so profuse you can't distinguish it from urine output and the splatter pattern is greater than 10 on a scale of 1-5.  He was on amoxicillin a month ago and the mother denies that he ate any spoiled food and gives you a look that leaves you as stunned as Senate Leader Mitch McConnel during his recent press conference.  His labs and physical findings are in the vignette. 

This is an example of the type of vignette you will encounter on both the American Board of Pediatrics Certification exam and the MOCA recertification process. 

What is your diagnosis and how would you establish the diagnosis ? 

How is it treated ? 

How do you prevent it ? 

Go ahead give it your best shot. Before we provide you with the answer we will show you how to decode the answers from the question itself. 

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Self Assessment Question and Answers 2019 Volume 3 Clinical Vignettes

Okay in breaking down and decoding the question itself we now know , it is not from contaminated food ( remember the mother's dirty look)  The physical exam and labs confirm significant dehydration. Based on this breakdown you should now know the diagnois,, how it can be confirmed, treated and prevented. Check it out below ! 

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