small bowel disorders Flashcards Preview

GI > small bowel disorders > Flashcards

Flashcards in small bowel disorders Deck (30)

What is celiac disease?

- autoimmune disorder that is triggered by an enviro agent (gliaden component in gluten) in genetically predisposed individuals
- it occurs primarily in whites of N european ancestry but has not increased in other ethnic groups
- reported prevalence in most countries: 1:70 to 1:300


2 components of gluten?

- gliadin and glutenin


What studies are used to follow course of CD?

- IgA abs to gliadin
- IgA abs to endomysium: a structure of smooth muscle CT, presence is nearly pathognomonic for CD
- gliadin receptors on intestinal epithelial cells may mediate the transport of gliadin peptides into lamina propria where T cell activation occurs - this may someday lead to drug therapy for CD


Mechanism of gluten irritation? Diff in bowel structure?

-gluten triggers release of protein that controls gut permeability
- intestinal lining cells are pried apart by protein, zonulin
- undigested food enters blood system
- immune system cells react by releasing cytokines. Which can trigger inflammation and disruption throughout the body
- this inflammation attracts more immune cells (macrophages) - just leads to more inflammation


Clinical manifestations of CD: classic?

- diarrhea with bulking, foul smelling, floating stools due to steatorrhea (malabsorption)
- wt loss
- vit deficiences: B vitamins, iron, copper, zinc, vit A, D, E and magnesium
- on small bowel bx: villous atrophy


Atypical disease presentation of CD?

- minor GI sxs
- can have anemia, osteoporosis, arthritis
- increased LFTs, neuro sxs, or infertility (due to abs)
- most show severe mucosal damage and possess the CD ab pattern


What is silent CD?

- recognized incidentally based upon screening for abs
- often have some changes in mucosa of small bowel
- they don't show clinical sxs but many complain of fatigue


Pts with CD have a slight increased risk for what malignancies?

- non-hodgkin lymphoma
- small intestinal adenocarcinoma
- hepatocellular carcinoma
- GI cancer
- lymphoproliferative disease
- hodgkin lymphoma

- decreased risk of breast cancer


Assoc conditions with CD?

- dermatitia herpetifromis (autoimmune rash)
- type 1 DM
- down syndrome
- liver disease
- autoimmune thyroid disease
- menstrual and repoductive issues in women
- infertility in men


How do you dx CD?

- begin with IgA anti-tissue transglutaminase (TTG): autoab against body's own transglutiminases
this is used for anyone over the age of 2, it is the single PREFERRED test for detection of CD

- if high prob of disease and IgA based serology is negative: test total IgA or IgG- deaminated gliadin peptides (DGP)
- pts with positive serology should undergo a small bowel bx:
- 1-2 bx from duodenal bulb
- at least 4 from 2nd and 3rd portion of duodenum


Other dx tests for CD?

- pts on gluten free diet who have negative serology's should have HLA/DQ1/DQ8 testing: determine if pt is genetically susceptible to disease, if negative CD is ruled out

- if serology is positive but small bowel bx is negative the pt can be put on high gluten diet and be rebx after 6-12 weeks
- individuals with low pretest probability (chinese, japanese, adn sub-saharan african descent): recommend - IgA endomysial ab test - it has a higher specifity but it is more costly


What is gluten sensitivity?

- some people are sensitive to gluten w/o having CD
- they get diarrhea, feel ill and bloated and find if they eliminate gluten from their diet they feel better


Tx of CD?

- consult with skilled dietitian
- education about disease
- lifelong adherence to gluten free diet
- Id and tx of nutritional deficiencies
- access to advocacy group
- continuous ongoing f/u by multidisciplinary team


What foods should be avoided in gluten free diet? What foods are ok?

- foods containing wheat, barley: avoid
- soybean or tapioca flours, rice, corn, buckwheat and potatoes are safe
- read labels: distilled alcohol, vinegar, and wine are gluten free
- beers, ales and malt vinegars often made with gluten
- dairy products may not be well tolerated initially since many pts with CD have secondary lactose intolerance - initially dairy should be avoided
- oats should be introduced into diet with caution (may be some cross reactivity)


How common is lactose intolerance in US - what ethnicities are mostly affected?

- 7-20% caucasian adults
- 80-90% native americans
- 55-65% african americans and africans
- 50% hispanics
- over 90% of some pops in East Asia


Sxs of lactose intolerance?

- due to low levels of lactase in small bowel:
- diarrhea
- abdominal pain
- flatulence


Mechanism of lactose intolerance?

- if you lose lactase - lactoce isn't being broken down this leads to bacterial fermentation- this is what causes sxs: loose stools, bloating, abd pain


Explain what racial/ethnic lactose malabsorption is?

- genetically regulated reduction in lactase activity determined by ethnic factors in healthy individuals
- majority of caucasians of N. European ancestry maintain elevated lactase levels as adults
- in US lactase activity is normal in all healthy children until 5


Explain what developmental lactase deficiency is?

- results from low lactase levels as result of prematurity
- infants born at 28-32 wks gestation have reduced lactase activity
- tx: use elemental (predigested) formula


What is congenital lactase deficiency?

- rare autosomal recessive disorder
- absence of any lactase activity in small intestine
- largest number of reported cases have been described in Finnish pop


What is secondary lactase malabsorption?

- bacterial overgrowth or stasis may be assoc with increased fermentation of dietary lactose in small bowel
- seen with any mucosal injury to small bowel such as gastroenteritis (avoid dairy products for a couple of weeks to allow mucosa to heal), CD, IBD


Clinical manifestations of lacose intolerance?

- abdominal pain: crampy, periumbilical and lower quadrants
- bloating
- flatulence
- diarrhea
- vomiting: adolescents


Dx of lactose intolerance?

lactose tolerance test:
- 50 g test dose given in adults
- blood glucose levels drawn at 0, 60, and 120 min
- an increase in blood glucose by less than 20 mg/dL plus sxs is dx
- this is cumbersome and time consuming

lactose breath hydrogen test:
- oral lactose given in fasting state (2 gm/kg - max: 25 mg)
- breath hydrogen levels measured at baseline and 30 min intervals for 3 hrs after lactose ingestion
- values over 20 ppm dx


Tx of lactose intolerance?

- dietary restriction of lactose intake: read labels, usually some lactose containing foods (cheese) can be tolerated
- substition of alt sources to maintain energy and protein intake
- admin of commercially available enzyme substrate: lactaid
- maintenance of Ca and Vit D intake


What is ileus?

- temporary absence of normal contractile movements to intestinal wall


Etiologies of ileus?

- post op: esp abdominal when the intestine's have been manipulated
- drugs: opioids and anticholinergics
- hypothyroidism
- lyte disorders: hypokalemia, hypercalcemia
- intestinal peritonitis: going to have rebound tenderness
- kidney failure
- pancreatitis - inflamed pancreas bothersome to bowel


Clinical manifestations of ileus?

- bloating
- N/V
- crampy abdominal pain: pain precedes vomiting when assoc with acute surgical etiology
- severe constipation
- loss of appetite


DDx of ileus?

-adynamic (paralytic) ileus (slowed down)
-intestinal obstruction
- acute abdomen
- post-op adhesive disease


Dx of ileus?

- xrays
- lytes
- CMP including Mg


Tx of ileus?

- NPO advancing to clear liquids as tolerated
- IV fluids to maintain hydration and correct lyte abnorm
- stop drugs that make ileus worse (use tordol, avoid opioids)
- occasionally NG tube
- if post op: get pt up and moving around