02a: IBD, diarrhea Flashcards
UC primarily associated with which symptom?
Bloody diarrhea
UC severe attack can be associated with (X), which has significant morbidity and mortality.
X = toxic mega colon (dilatation of colon)
UC begins in (X) and spreads (proximally/distally). It (always/sometimes/never) involves entire colon. It is (always/sometimes/never) transmural inflammation.
X = rectum
Proximally
Sometimes
Never
T/F: 70% of patients with UC have involvement of entire colon
False - 70% don’t have involvement proximal to sigmoid colon
What is proctitis?
Inflammation limited to rectum
Patient recently diagnosed with UC asks about his likelihood of needing Colectomy. You tell him that overall, (X)% of UC patients require this procedure.
X = 20-25
List the findings you would expect to see on colonoscopy in patient with new UC.
- Granular erythematous mucosa
- Decreased blood vessel markings
- Ulcerations (deeper with exudate in severe cases)
What finding on colonoscopy would lead you to believe patient has long-standing UC?
Pseudopolyps (islands of normal tissue in region of previous ulceration)
Colonic biopsy reveals (X) in UC.
Crypt distortion/abscesses with leukocyte (PMNs, eosinophils, lymphocytes) infiltration
Why is toxic megacolon so dangerous?
High risk of perforation
List the 3 patterns of distribution seen in Crohn’s.
- Ileocolitis (40% of patients)
- Confined to small intestine - ileitis/jejunoileitis (30%)
- Confined to colon (Crohn’s colitis, 25%)
T/F: Crohn’s can involve esophagus
True - any part of GI tract
List the predominant symptoms of Crohn’s.
Abdominal pain, diarrhea, weight loss
Patient recently diagnosed with Crohn’s asks about his likelihood of needing surgery. You tell him that within a decade, (X)% of Crohn’s patients require surgical intervention.
X = over 60%
And 40% require repeat intervention within 5 y after first surgery
T/F: Crohn’s inflammation is diffuse and transmural.
Partly false - focal and transmural
In (Crohn’s/UC), “creeping fat” refers to (X) phenomenon. The mucosa has (Y) appearance due to edema and linear ulceration.
Crohn’s
X = mesentery becomes infiltrated with fat
Y = cobblestone
Histological presence of (caseating/non-caseating) granulomas are characteristic of (Crohn’s/UC).
Non-caseating
Crohn’s
Malabsorption of (X) and development of megaloblastic anemia is a complication of which IBD?
X = vitamin B12
Crohn’s
Development of fistulas is seen in (UC/Crohn’s). What structures can involve this fistula formation?
Crohn’s
- Enteroenteric
- Between colon and other organs (bladder, vag)
- Enterocutaneous
Chronic (X) malabsorption in (UC/Crohn’s) puts patients at increased risk for (Y) urinary stone development.
X = fat (binds Ca in gut, frees oxalate)
Crohn’s
Y = Ca-oxalate
What is the most common extra-intestinal manifestation of IBD?
Arthritis (peripheral or axial)
Patients with (UC/Crohn’s) are 30x increased risk of (X) axial arthritis, (because/despite) HLA-B27 positivity (is/isn’t) increased in this IBD.
UC
X = spondyloarthritis
Despite
Isn’t
Which classic dermatological findings would you see in IBD? Name the locations you would likely see these.
- Erythema nodosum (anterior tibia)
2. Pyoderma gangrenosum (legs)
Routine checkup for patient with UC. Your notice a foot ulcer with necrotic base, called (X). How do you treat?
X = pyoderma gangrenosum
Systemic or intralesional steroids
Your patient with Crohn’s comes in complaining of blurred vision, headache, and photophobia. Which complication has occurred and which Rx do you propose?
Uveitis
Local steroids or atropine
List the three major diagnostic techniques used for IBD.
- Stool studies (rule out infection)
- Endoscopy (maybe biopsy)
- Radiography (CT/MR)
When might videocapsule endoscopy be used to diagnose IBD?
In Crohn’s involving small bowel when other imaging techniques aren’t diagnostic
Abdominal mass is commonly felt in (Crohn’s/UC).
Crohn’s
Pseudopolyps are seen in (Crohn’s/UC).
Both
Presence of perianal disease is characteristic of (Crohn’s/UC).
Crohn’s
T/F: Rx for IBD is now based on symptoms.
False - paradigm shift; now treat based on markers of inflammation
Mild IBD Rx includes:
- Aminosalicylates (sulfasalazine)
- Nutritional modification (peds)
- Antibiotics
Moderate IBD Rx includes:
- Azthioprine, MTX
2. Corticosteroids
Severe IBD Rx includes:
- IV steroids
- Cyclosporine
- Surgery
T/F: patients with moderate/severe IBD are on corticosteroids for maintenance purposes when in remission.
False
Diarrhea officially defined as:
Stool weight greater than 200g/day
Clinically, patients describe diarrhea as change in stool:
Frequency, consistency, or volume
Chyme is made (hyper/iso/hypo)-tonic in (X) part of gut and remains so throughout the rest of the tract.
Isotonic (with plasma, via fluid shifts)
X = duodenum
“Dumping syndrome” is the result of resection of (X) part of bowel. Patients have which symptoms and why?
X = pyloric sphincter (no regulation of chyme entering small bowel)
Cramps and hypotension after meals (lots of IV volume lost due to fluid shifts when hypertonic chyme enters duodenum all at once)
Along intestinal tract, (X) provides driving force for Na (reabsorption/secretion) via which transporters?
X = Na/K pump
Reabsorption
- Na/glucose symporter
- Na/H antiporter
Along intestinal tract, Cl is (reabsorbed/secreted) via which transporter?
Reabsorbed
Cl/HCO3 exchanger
In the colon, Na primarily (absorbed/secreted) via which mechanism?
Absorbed
Passive diffusion through channels
K is actively (absorbed/secreted) in (small/large) bowel, so stool is (higher/lower) in K than chyme
Secreted
Large
Higher
Intestinal fluid secretion is highly dependent on (X) (reabsorption/secretion) and relies on (Y) transporter in which intestinal cells?
X = Cl
Secretion
Y = Na/K/2Cl (basolateral)
Crypt cells
List the three specific second messenger systems have been identified in the secretion of intestinal fluid
- cAMP
- cGMP
- Ca (intracellular)
Increase in cAMP will (increase/decrease) activity of CFTR and (increase/decrease) Na and Cl absorption.
Increase (increase Cl secretion)
Decrease reabsorption
T/F: increase in cAMP levels will decrease glucose absorption due to decrease Na/glucose transporter activity.
False - doesn’t affect this
What’s the prototypical illness leading to marked intestinal secretion and diarrhea? How does this infectious organism work?
Cholera
Toxin activates AC and increases cAMP levels
An important advance in the treatment of secretory diarrheas such as cholera is the use of (X), which take advantage of (Y) transporters.
X = oral rehydration solutions (ORS) Y = Na/glucose
Oral rehydration solutions (ORS) contain appropriate balance of which solutes?
NaCl and simple sugars
(X)-secreting pancreatic tumors develop an illness similar to cholera called the (Y) syndrome. What’s the mechanism behind this?
X = VIP Y = WDHA (watery diarrhea, hypokalemic acidosis)
VIP increases secretions via cAMP-dependent mechanism
T/F: E. coli toxin, like cholera, produces watery diarrhea via cAMP mechanism.
False - via cGMP
Serotonin (increases/decreases) intestinal secretions via which mechanism?
Increases
Increases intracellular Ca influx via basolateral membrane
Patients who have had resections of their distal ileum are prone to (diarrhea/constipation) due to decrease in (X) reabsorption.
Diarrhea
X = bike acids (promote intestinal secretion)
What are the two main mechanisms by which osmotic diarrhea occurs?
- Ingestion of poorly absorbed solutes (laxatives, Mg, sorbitol)
- Malabsorption
Which clinical methods are used to distinguish between secretory and osmotic diarrhea?
- 48h fast
2. Measure stool Osm
Patient with diarrhea recovers after a 48h fast with IV fluids. She had (secretory/osmotic) diarrhea, and you would expect stool Osm gap to be (X).
Osmotic
X = increased (over 100)
Calculated stool osmolarity is:
2x(Na+K)
