DSA 6: Diarrhea DSA Flashcards
What electrolytes are usually lost due to diarrhea?
Bicarbonate and potassium
Which type of acute diarrhea usually does not need any work up because it is self-limited?
Non-inflammatory
With inflammatory acute diarrhea would should be performed for all patients?
Routine stool bacterial cultures including E. coli 0157:H7
What is the most common cause of non-infectious diarrhea that occurs greater than 14 days?
Medications such as antibiotics and NSAIDs
What food sweeter is a common cause of non-infectious diarrhea?
Sorbitol (found in chewing gum)
What is acute diarrhea defined as?
What is chronic diarrhea defined as?
1) Less than two weeks duration
2) Greater than four weeks duration
What are some clues that lean towards osmotic diarrhea?
1) Stool volume decreases with fasting
2) Increased stool osmotic gap
What should patients be asked about if they present with osmotic diarrhea?
Their intake of dairy products (lactose), fruits and artificial sweeteners (fructose and sorbitol), and alcohol
What is a major dietary cause of osmotic diarrhea?
How is it diagnosed?
1) Lactose intolerance
2) Hydrogen breath test
What are some clues that lean towards secretory diarrhea?
1) Stool volume doesn’t change with fasting
2) Normal stool osmotic gap
3) High volume watery diarrhea
What does secretory diarrhea lead to?
1) Dehydration
2) Hyponatremia
3) Non-anion gap metabolic acidosis
What types of tumors are common causes of secretory diarrhea?
Endocrine tumors like ZE syndrome
What are the three most common causes of chronic diarrhea?
What symptoms are inconsistent with these common causes and warrant further evaluation?
1) Meds, IBS, Lactose intolerance
2) Nocturnal diarrhea, weight loss, anemia, or positive FOBT
Fecal leukocytes, fecal calprotectin, and fecal lactoferrin may suggest?
IBD
What is a more sensitive and specific method than wet mount when testing for Giardia and E. histolytica?
Fecal antigen test
What do most patients with chronic persistent diarrhea undergo in order to exclude IBD, microscopic colitis, and colonic neoplasia?
Colonoscopy with mucosal biopsy
What is performed when a small intestinal malabsorptive disorder is suspected?
EGD with small bowel biopsy
If malabsorption is suspected what is used to determine if the cause is pancreatic insufficiency?
What is used to determine if the cause is due to chronic pancreatitis?
1) Fecal elastase less than 100 mcg/g
2) Calcification on a plain abdominal radiograph
Presence of what symptoms should make you lean away from diagnosis of IBS and warrant investigation for an underlying disease?
1) Acute onset
2) Nocturnal diarrhea
3) Severe constipation or diarrhea
4) Hematochezia
5) Weight loss
6) Fever
What is IBS characterized by?
1) Altered bowel habits
2) Abdominal pain
3) Absence of detectable organic pathology
What is the diagnostic criteria used for IBS?
ROME IV Clinical Diagnostic Criteria
Hydrogen breath test is used to diagnose?
Lactase deficiency
What is the most common cause of antibiotic associated colitis?
C. diff
Is C. diff aerobic or anaerobic?
Is it gram + or - ?
Sporulating or non?
Shape?
1) Anaerobic
2) Gram positive
3) Spore forming
4) Bacillus
C. diff toxins A and B cause?
Mucosal damage
What are the most common antibiotics that cause C. Diff infection?
1) Ampicillin
2) Clindamycin
3) Third-generation cephalosporins
4) Fluoroquinolones
What would be in the CBC that pointed towards C. diff?
Leukocytosis: white blood count > 15,000/mcL
What is found on flexible sigmoidoscopy for C. diff patients?
What do biopsies reveal epithelial ulceration with a classic?
1) Yellow pseudomembranous colitis
2) Volcano exudate of fibrin and neutrophils
When should alcohol sanitizer be used in order to minimize the transmission of C. diff?
Never, always wash hands with soap and water
What complications can C. diff cause?
Toxic megacolon and hemodynamic instability
What are the characteristics of malabsorption syndromes?
1) Weight loss
2) Steatorrhea
Celiac disease is an immunologic response to what storage protein?
It causes diffuse damage to?
1) Gluten
2) Proximal small intestinal mucosa
Celiac disease is only present in people with?
It causes antibodies to?
1) HLA-DQ2 or HLA-DQ8
2) Gluten and IgA tissue
transglutaminase (tTG)
What atypical symptom of celiac causes pruritic papulovesicles over the extensor surfaces of the extremities and over the trunk, scalp, and neck?
Dermatitis herpetiformis
Celiac disease leads to what histologic finding?
What is seen on endoscopy?
1) Complete loss of intestinal villi
2) Atrophy or scalloping of the duodenal folds
Where are bile salts reabsorbed?
Problems with this process can be seen in what conditoin?
1) Terminal ileum
2) Crohn’s disease
Bile salt malabsorption causes impaired absorption of what, leading to bleeding tendencies, osteoporosis, and hypocalcemia?
What type of diarrhea is seen?
1) Fat-soluble vitamins (A, D, E, K)
2) Watery secretary
What rare multisystem disease presents with weight loss, malabsorption, chronic diarrhea and is due to infection with a gram positive bacillus that is not acid fast?
What is the name of that bacteria?
1) Whipple disease
2) Tropheryma whipplei
What is diagnostic of whipple disease with endoscopy with duodenal biopsy?
Periodic acid Schiff positive for macrophages with characteristics bacillus
What conditions does pseudo-diarrhea accompany?
IBS or proctitis
What is severe constipation where only the only contents that gets by is liquid?
Overflow diarrhea
What population is overflow diarrhea most common in?
Elderly
What medication is a common cause of constipation?
Opioids
What are three reasons not to do a digital rectal exam?
1) You don’t have a finger
2) The patient doesn’t have a rectum
3) The patient has leukopenia
Chronic use of laxatives can lead to?
Melanosis coli (a benign hyperpigmentation of the colon)
