Let's Learn About Loose Watery Stools
A patient comes into your clinic with 4 watery stools a day for the past 66 days. As the astute physician you are, you diagnose the patient with
chronic diarrhea
Weight below ____ or a drop in weight across _____ is defined as a failure to thrive
5th percentile; 2 major percentile lines
A 22-year-old college student develops profuse, non-bloody, watery diarrhea and vomiting 24 hours after attending a dormitory potluck dinner. Several classmates who ate the same salad are also ill. Symptoms resolve spontaneously within 48 hours without treatment.
Norovirus
I'm a piece of viral RNA that has undergone reverse transcription and amplification. What test was performed on me?
Typhoid Mary
Salmonella
Viruses, bacteria, and parasites cause ____ diarrhea
infectious diarrhea
_____ refers to a decrease in total body water whereas _____ refers to a depletion of extracellular volume
dehydration, hypovolemia
A 35-year-old man presents with 5 days of bloody diarrhea, abdominal cramps, and fever after returning from a trip to rural Mexico. Stool microscopy reveals organisms with ingested red blood cells.
Entamoeba histolytica
Blood cultures are typically used to identify _____ in infectious diarrhea
bacteremia
O157:H7, hemolytic uremic syndrome
STEC
Name three red flag symptoms when assessing a patient's diarrhea
fever, hypotension, severe dehydration, bloody stools, severe abdominal pain, chronic illness, immunocompromised, age > 65 yrs, recent antibiotic use, > 48 duration without improvement
Identify the classic triad of symptoms associated with zinc insuffiency
Acral dermatitis, alopecia, diarrhea
A 68-year-old hospitalized woman develops foul-smelling, watery diarrhea 10 days into a course of clindamycin for a wound infection. She is febrile to 38.6°C and has a leukocytosis of 22,000/μL. CT abdomen shows diffuse colonic wall thickening.
Clostridioides difficile (C. difficile)
How do you calculate the stool osmolar gap?
290 - 2(stool Na - stool K)
Avoid in invasive diarrhea
Loperamide
This medical term is defined as a condition of intestinal infection and inflammation that results in mucoid-bloody diarrhea with an inflammatory exudate composed of polymorphonuclear leukocytes. Causative pathogens include Shigella and Entamoeba histolytica.
dysentery
A child comes into your clinic. On standardized charts, he is in the 4th percentile. The physician suggests that the child undergoes a sweat test. This test is primarily used to diagnose what medical condition?
cystic fibrosis
A 4-year-old girl presents with a 3-day history of bloody diarrhea following consumption of undercooked ground beef at a family barbecue. Labs reveal hemoglobin 7.2 g/dL, platelets 45,000/μL, creatinine 3.1 mg/dL, and schistocytes on peripheral smear. Stool culture grows a non-sorbitol-fermenting organism.
STEC (Shiga toxin–producing E. coli)
In addition to taking a detailed history, a physician must perform this exam to determine if a patient has fecal incontinence.
Digital rectal examination
Daycare outbreaks, pseudoappendicitis
Yersinia enterocolitica
Patient A comes into the clinic with watery diarrhea. After standard clinical workup, they are diagnosed with thyroid cancer. You note a stool osmolar gap of 37 mOsm/kg
Patient B also comes into the clinic with watery diarrhea. After standard clinical workup, they are diagnosed with pancreatic insufficiency. You note a stool osmolar gap of 105 mOsm/kg.
Your attending physician tells you that while Patient A and Patient B both came into the clinic with watery diarrhea, the pathophysiology differed between the two patients. Explain what that difference is.
Patient A had secretory diarrhea which is defined as active secretion of water into the lumen. Common causes include neuroendocrine disorders and foodborne infections
Patient B had osmotic diarrhea which is defined as water being drawn into the lumen due to an osmotic substance. Common causes include malabsorption (Celiac Disease), laxatives, and pancreatic insufficiency
A patient comes into the emergency room with gastroenteritis which has led to intense vomiting and diarrhea, tachycardia, hypotension, hypovolemia, and reduced organ perfusion.
Your attending physician notes dehydration in his SOAP note, but as a smart and savvy medical student, you decide to make an addendum adding more detail to characterize the patient's dehydration. How would you classify this patient's dehydration?
severe isotonic dehydration
Categorization by Severity (Clinical Assessment)
A 32-year-old man with AIDS (CD4 count 45 cells/μL) presents with chronic, large-volume, non-bloody watery diarrhea and 15-pound weight loss over 2 months. Multiple stool cultures for bacteria are negative. Modified acid-fast stain of the stool reveals small (4–6 μm), round, variably staining oocysts. Symptoms do not improve with standard antibiotics, and upper endoscopy with small bowel biopsy shows organisms along the brush border of enterocytes.
Cryptosporidium
A 23-year-old woman presents with a 6-month history of fatigue, intermittent diarrhea, and increasing abdominal pain. She has recently noted unintentional weight loss and iron deficiency anemia that does not respond to iron supplements. You suspect that the patient has celiac disease. What procedure would be necessary to confirm this diagnosis
Upper endoscopy
stool pH < 6
carbohydrate malabsorption