02b: Malabsorptive Disorders Flashcards
Worldwide, (X) is the most common cause of malabsorption.
X = Infestation (Giardia and other organisms)
In industrialized societies, the common causes of malabsorption are: (star the two most common)
- Lactose intolerance*
- Celiac disease*
- Pancreatic insufficiency
- Bacterial overgrowth
Chronic pancreatitis causes malabsorption via which mechanism? Which other diseases have this similar effect?
Lack of pancreatic enzymes/HCO3 (failure of digestion)
CF, pancreatic cancer
Bacterial overgrowth causes malabsorption via which mechanism? Which other diseases have this similar effect?
Lack of bile salts (defective micelle formation)
Obstructive jaundice, cholestatic liver disease, bile salt loss (ex: resection of terminal ileum)
List some disease states that cause malabsorption due to loss of villi surface in small bowel.
- Celiac
- Post-infectious
- Whipple’s disease
- Crohn’s
Patient describes stool as light-colored and sticky to the toilet bowl. This is suggestive of (X) from (Y) malabsorption.
X = steatorrhea Y = fat
CHO malabsorption: you would expect diarrhea to be (secretory/osmotic).
Osmotic (unabsorbed osmoles promote water movement into lumen)
Fat malabsorption: you would expect diarrhea to be (secretory/osmotic).
Secretory (lipids metabolized by bac in colon to produce FA that promote secretion)
Patient with diarrhea and night blindness is likely deficient in (X).
X = Vit A
Patient with diarrhea and easy bruising is likely deficient in (X).
X = Vit K
Patient with diarrhea and peripheral neuropathy is likely deficient in (X).
X = Vit B12
Edema is a common physical finding in malabsorption of:
Protein
Clubbing of fingers is a finding suggestive of which GI issue?
IBD
What is angular stomatitis? It’s suggestive of (X) deficiency.
Inflammation on sides of mouth;
X = Iron
Glossitis is suggestive of (X) deficiency.
X = Iron and vitamin B
Aphthous ulcers are commonly found in which malabsorptive disease(s)?
Celiac’s and Crohn’s
ZES causing (low/high) duodenal pH will cause (CHO/fat) malabsorption via which mechanisms?
Low; fat
- Inhibits fat digestion by pancreatic lipase
- Decrease bile salt solubility
Bacterial overgrowth occurs in (small/large) bowel and is clinically diagnosed by (X).
Small;
X = breath test (orally administered CHO metabolized by intraluminal bac and CO2/H measured)
What would constitute an “abnormal” breath test, indicating bacterial overgrowth?
H2 exhaled in breath detected earlier than normal (since overgrowth occurs in small bowel and normal bacteria is colonic)
T/F: Pts with bacterial overgrowth are treated with antibiotics.
True - rifaximin, tetracycline, and ciprofloxacin for a week or so
Protein losses/malabsorption is more common in (pancreatic/intestinal) diseases.
Intestinal (absorption);
Both protein and CHO digestion can be maintained until over 90% of pancreatic function (protease/amylase secretion) is lost
CHO maldigestion is often the result of defective (X).
X = brush border hydrolases (convert oligos into monosacc)
Why would hyperthyroidism cause CHO malabsorption?
Rapid transit states don’t allow brush border enzymes enough time for adequate digestion
T/F: Lactase is a brush-border enzyme.
True
(X) is a non-absorbable CHO used to treat constipation.
X = lactulose
Celiac disease: etiology?
Enteropathy resulting from mucosal sensitivity to gliadin proteins of gluten (in wheat, barley, rye)
Celiac disease primarily affects (proximal/distal) (small/large) bowel.
Proximal small bowel
(X) deficiency is very common in celiac disease.
X = Fe
Most Celiac patients present with (X) complaint. What other symptoms may they complain of?
X = diarrhea (and maybe steatorrhea)
Weight loss, malaise, anemia, osteoporosis
Children with Celiac disease will present with:
failure to thrive or growth retardation
Virtually all patients with (X) skin finding have Celiac disease.
X = dermatitis herpetiformis
Which autoimmune disorders are common in Celiac disease?
DM and thyroid diseases
How is Celiac diagnosis confirmed (gold standard)?
Small bowel biopsies (before and on treatment)
Classic histo findings of Celiac disease biopsy.
Absent villi, crypt hyperplasia;
Increase in intra-epithelial lymphocytes
T/F: Histo changes in Celiac disease are specific to it.
False - but small bowel should return to normal after complete gluten withdrawal (hence need to re-biopsy during treatment)
Which serological test has super high sensitivity and specificity for diagnosing Celiac disease?
IgA tissue transglutaminase
An elevated INR, aka (X), suggests (Y) deficiency. How do you treat?
X = prothrombin time (suggests coagulopathy) Y = vitamin K
Parenteral administration of vitamin K
(X) cancer is strongly associated with celiac sprue, especially in patients who have long-standing untreated disease or disease refractory to Rx.
X = malignant lymphoma (usually of T cells)
T/F: Carcinoma incidence is increased in patients with Celiac sprue.
True - small intestine adenocarcinoma
Which histological findings are characteristic of Whipple’s disease?
Lamina propria of villi distended by large macrophages with PAS-positive granules (actinomyces bacilli on EM)
You suspect your patient with IBD has infectious colitis. Which test do you run to verify it isn’t just an IBD flare?
Biopsy
You suspect your patient with IBD has infectious colitis. Which findings on biopsy suggest cause is infectious, not IBD flare?
preservation of non-branched normal crypt architecture in the face of active inflammation and repair
(X) colitis is seen in early acute ischemic injury and characterized by the presence of multiple (Y) on the mucosa.
X = pseudomembrane Y = white patches (of mucus and polys) with adjacent patches of normal mucosa
(X) infectious agents induce a histologic abnormality similar to pseudomembrane colitis. Briefly describe this type of colitis.
X = cytotoxin of E. coli (0157: H7) and C. dificle
Severe ISCHEMIC necrotizing-type colitis
Pt presents with watery diarrhea. Endoscopy reveals normal colon and rectum. Biopsy shows degenerative changes of the surface epithelium associated with lymphocytic infiltration. What’s the diagnosis?
Microscopic colitis
Surgical resection specimen from a patient with UC shows a (X) mucosa, (shallow/deep) ulcers and the rectum (always/sometimes/never) involved. The bowel is (shortened/lengthened) wish loss of (Y) due to muscle (hyper/hypo)-trophy.
X = red, bloody Shallow Always Shortened Y = haustra Hypertrophy
The most common parasitic infestation in humans, often encountered in biopsy of (X) portion of GI tract.
Giardia Lamblia
X = small intestine
How would colonic glands microscopically differ in acute v chronic UC?
Acute: branching glands (manifestation of injury and repair)
Chronic: GLAND ATROPHY
Patchy inflammation with “skip” areas is characteristic of which IBD?
Crohn’s
PAS stain is used to diagnose (X) malabsorptive disorder. Characteristic finding is bright (Y)-color due to staining of:
X = Whipple's disease (T. whipplei infection) Y = magenta
Glycoproteins on cell wall of bacteria
PAS stain in Whipple’s disease will characteristically show (X) cells in (Y) tissue layer of intestines.
X = PAS-positive foamy macrophages Y = lamina propria
