JH IM Board Review - Disorders of the Small and Large Intestine I Flashcards Preview

► Med - Internal Medicine > JH IM Board Review - Disorders of the Small and Large Intestine I > Flashcards

Flashcards in JH IM Board Review - Disorders of the Small and Large Intestine I Deck (114)
Loading flashcards...
1
Q

Diseases that affect the intestinal system are likely to interfere with at least one of these 2 functions and lead to problems with:

A
  1. Motility.

2. Malabsorption.

2
Q

Diarrhea - General principles - Definition:

A

Incr. in fluidity, frequency, or volume of stool output.

==> Usually results in increased daily stool weight (>200g/day).

3
Q

Diarrhea can be described by many features:

A
  1. Osmotic vs secretory.
  2. Bloody vs nonbloody.
  3. Inflammatory vs non inflammatory.
  4. Steatorrhea vs normal fat content.
  5. Infectious vs non infectious.
4
Q

5 Mechanisms of diarrhea:

A
  1. Osmotic.
  2. Secretory.
  3. Abnormal motility.
  4. Abnormal mucosa/Exudative.
  5. Anorectal dysfunction.
5
Q

Osmotic - Comments:

A
  1. Small stool volume.
  2. Osmolar gap present.
  3. Stops with fasting.
  4. Stool pH <6.
6
Q

Secretory - Comments:

A
  1. Large volume of stool.
  2. No osmolar gap.
  3. Persistent diarrhea with fasting.
7
Q

Abnormal motility - Comments:

A

Bacterial overgrowth motility usually secondary to decreased motility.

8
Q

Abnormal mucosa/ exudative - Comments:

A

Volume can be small or large.

9
Q

Anorectal dysfunction:

A

Small volume of stools.

10
Q

Osmotic - Examples:

A
  1. Maldigestion of carbs (eg lactose, fructose).
  2. Ingestion of nonabsorbed solutes (eg mannitol, sorbitol).
  3. Ingestion of poorly absorbed salts (magnesium, hydroxide).
11
Q

Secretory - Examples:

A
  1. Bacterial toxins (eg cholera, E.coli).
  2. Hormonal secretagogues (Eg VIP, serotonin).
  3. Gastric hypersecretion (eg Z-E).
  4. Laxatives (eg senna, phenolphthalein).
  5. Bile salt malabsorption.
12
Q

Abnormal motility/exudative - Examples:

A
  1. IBD.
  2. Bacterial pathogens (eg Salmonella, Shigella).
  3. Vasculitis.
  4. Radiation enteritis.
  5. Severe diverticulitis.
  6. Ischemic injury.
13
Q

Anorectal dysfunction - Examples:

A
  1. Neurologic disease.
  2. Postsurgical complication.
  3. IBD.
14
Q

Osmotic diarrhea - Features:

A
  1. Diarrhea stops when oral intake stops.

2. Volume is usually LESS THAN 1lt/day.

15
Q

Altered motility - INCREASED:

A
  1. Causes decreased contact time between the gut and digesting food (chyme).
  2. Leads to less absorption and large amounts of fluid delivered to the colon.
16
Q

Altered motility - Decreased motility:

A
  1. Causes bacterial overgrowth.

2. Leads to impaired bile salt malabsorption.

17
Q

Altered mucosa and exudative diarrhea:

A
  1. Inflamed or ulcerated mucosa permits mucus, blood, and pus to leak into lumen.
  2. Diarrhea can result directly from the increased osmotic load, increased motility (stimulation of the enteric nervous system), or secretion of the products of inflammation.
  3. Stool volume can be large or small, depending on the part of the bowel affected.
18
Q

BLOODY diarrhea can be related to:

A
  1. Campylobacter.
  2. Shigella.
  3. Salmonella.
  4. E.coli.
  5. Amebiasis.
  6. IBD.
  7. Malignancy.
  8. Adenocarcinoma.
  9. Colitis (ischemic or infectious).
19
Q

Anorectal dysfunction or injury:

A
  1. Leads to the inability to retain feces.

2. Characterized by fecal incontinence and small-volume stools.

20
Q

Most diarrheal illnesses have more than …?

A

One mechanism of stool generation (eg diseases of malabsorption).

21
Q

Acute diarrhea:

A
  1. Usually self-limited (shorter than 4 weeks’ duration).
  2. Most cases infectious.
  3. Consider medications (eg laxatives, Mg-containing antacids, PPIs, colchicine, furosemide).
22
Q

If abdominal pain and bloody diarrhea occur together in a patient older than 50 or with known vascular disease …?

A

Consider ISCHEMIC COLITIS.

23
Q

Chronic diarrhea - Lasts:

A

Longer than 4 weeks.

24
Q

Steatorrhea is defined as …?

A

More than 7g of fat/day over 72h fecal fat collection while on a high-fat diet (100g fat/day).

25
Q

Associated signs/symptoms that suggest an organic rather than a functional (IBS) cause are:

A
  1. Fever.
  2. Weight loss.
  3. Arthritis.
  4. Anemia.
  5. Signs of malabsorption.
26
Q

Acute diarrhea in an immune-competent patient does NOT require …?

A

Evaluation. UNLESS signs of:

  1. Dehydration.
  2. Bloody stools.
  3. Fever.
  4. Severe abdominal pain.
27
Q

Selected causes of chronic diarrhea - Infections:

A
  1. Amebiasis.
  2. Giardiasis.
  3. C.diff.
  4. HIV enteropathy.
  5. Yersinia.
  6. Campylobacter.
  7. Cryptosporidium.
  8. Cyclospora.
  9. Intestinal schistosomiasis.
28
Q

Selected causes of chronic diarrhea - Inflammatory:

A
  1. IBD.
  2. Microscopic colitis.
  3. Eosinophilic gastroenteritis.
29
Q

Selected causes of chronic diarrhea - Hormonal abnormalities/tumors:

A
  1. Diabetes.
  2. Hyperthyroidism.
  3. Adrenal insufficiency.
  4. VIPomas.
  5. Carcinoid syndrome.
  6. Medullary thyroid cancer.
  7. Gastrinoma.
  8. Mastocytosis.
30
Q

Selected causes of chronic diarrhea - Nonendocrine neoplasms:

A
  1. Villous adenoma secreting bicarbonate.

2. Obstructive colon cancer causing impaction and overflow diarrhea of liquid feces.

31
Q

Selected causes of chronic diarrhea - Steatorrheal causes - maldigestion:

A
  1. Pancreatic exocrine insufficiency.
  2. Bacterial overgrowth.
  3. Liver disease.
32
Q

Selected causes of chronic diarrhea - Steatorrheal causes - mucosal malabsorption:

A
  1. Celiac sprue.
  2. Tropical sprue.
  3. Whipple.
  4. Ischemia.
33
Q

Selected causes of chronic diarrhea - Structural:

A
  1. Bile salt diarrhea after ileal resection.
  2. Vagotomy.
  3. Short bowel syndrome.
34
Q

Selected causes of chronic diarrhea - Osmotic:

A
  1. Laxatives (Mg).
  2. Carb enzyme deficiencies (eg lactase).
  3. Sorbitol.
  4. Lactulose ingestion.
35
Q

Selected causes of chronic diarrhea - Functional:

A

IBS.

36
Q

Selected causes of chronic diarrhea - Anorectal dysfunction:

A

Neurologic.

37
Q

Stool electrolytes (Na and K) for calculating osmolar gap:

A

Osmolar gap = 290 - (Na + K) x 2.

If >40 ==> OSMOTIC diarrhea likely.

If <40 ==> SECRETORY diarrhea likely.

38
Q

Nutrient malabsorption - Proximal small bowel:

A
  1. Iron.
  2. Calcium.
  3. Folate.
39
Q

Iron malabsorption:

A
  1. Glossitis.
  2. Pallor.
  3. Anemia.
  4. Pica.
40
Q

Calcium malabsorption:

A
  1. Bone pain.
  2. Tetany.
  3. Osteoporosis.
41
Q

Folate malabsorption:

A
  1. Glossitis.
  2. Pallor.
  3. Anemia.
  4. Depression.
42
Q

Nutrient malabsorption - Distal small bowel:

A

ADEK + B12.

43
Q

VitA malabsorption:

A
  1. Night blindness.
  2. Hyperkeratosis.
  3. Corneal ulcers.
44
Q

VitD malabsorption:

A
  1. Bone pain.
  2. Muscle weakness.
  3. Osteomalacia.
45
Q

VitE malabsorption:

A
  1. Peripheral neuropathy.

2. Retinopathy.

46
Q

VitK malabsorption:

A
  1. Bleeding.

2. Easy bruising.

47
Q

Tests for malabsorption:

A
  1. D-xylose test.
  2. Hydrogen breath test for lactose intolerance.
  3. Hydrogen breath test for bacterial overgrowth.
48
Q

D-xylose test:

A
  1. Measures the absorptive capacity of the proximal small bowel.
  2. Urine and blood are collected after 25g oral xylose is administered.
  3. Abnormal test suggests bowel mucosal disease or bacterial overgrowth.
  4. Normal test in pancreatic enzyme deficiency.
49
Q

Hydrogen breath test for lactose intolerance:

A
  1. Tests for lactose digestion.
  2. After ingestion of lactose, the amount of hydrogen in expired air is measured.
  3. If substantial levels are recorded, lactose intolerance is suggested.
50
Q

Alternative test to hydrogen breath test for lactose intolerance?

A

Dietary restriction followed by milk challenge.

==> If dietary rechallenge produces typical symptoms, lactose maldigestion is likely.

51
Q

Hydrogen breath test for bacterial overgrowth:

A
  1. Tests for lactulose digestion.
  2. After ingestion of lactulose, the amount of hydrogen and methane in expired air is measured.
  3. If substantial levels are recorded, bacterial overgrowth is suggested.
52
Q

Celiac disease (gluten-sensitive enteropathy) - Basic info:

A
  1. Predominantly seen in white population.
  2. Flattened villi of the proximal small bowel.
  3. HLA-DQ2/DQ8 ==> Genetic testing should NOT be routinely performed.
53
Q

Celiac disease - Serology studies:

A

Tissue transglutaminase IgA.

==> 1/200 prevalence in the USA.

54
Q

Celiac disease - Clinical presentation - Diarrhea?

A

Diarrhea is common but might NOT be present.

55
Q

Celiac disease - Clinical presentation - Iron-deficiency anemia?

A

In 50% of adults with celiac disease.

56
Q

Celiac disease - Clinical presentation - Osteomalacia and osteoporosis?

A

From vitD malabsorption + Ca malabsorption.

57
Q

Celiac disease - Clinical presentation - Most adults present with features of malabsorption?

A

NO.

58
Q

Celiac disease - Clinical presentation - ALT, AST?

A

Elevated in 42%.

==> Liver function will return to normal when placed on gluten-free diet.

59
Q

Celiac disease - Clinical presentation - Dx?

A

Is often DELAYED for many years after the onset of symptoms.

60
Q

Celiac disease - Clinical presentation - Patients often have also …?

A

IBS.

61
Q

Celiac disease - Clinical presentation - Associated with a number of diseases?

A
  1. Dermatitis herpetiformins.
  2. DM I (+ other autoimmunes).
  3. Autoimmune hep.
  4. Autoimmune thyroid disease.
  5. Down, Turner, Williams.
  6. Small bowel lymphoma.
62
Q

Dermatitis herpetiformis:

A

Papulovesicular rash usually on the elbows, knees, buttocks, or scalp.

63
Q

Celiac disease - Dx and evaluation - Initial screening:

A

Antibody testing:

==> Check total serum IgA + Tissue transglutaminase (tTG) IgA as first-line screening.

64
Q

Celiac disease - Dx and evaluation - Antiendomysial antibody:

A

IgA that is 85-98% sensitive + 97-100% specific.

65
Q

Celiac disease - Dx and evaluation - Tissue transglutaminase IgA antibody:

A

90-98% sensitive + 95-97% specific.

66
Q

Celiac disease - Dx and evaluation - Antigliadin antibody IgG and IgA:

A

Lower sensitivity and specificity.

67
Q

Celiac disease - Dx and evaluation - If there is high suspicion, but tTG IgA is negative, further tests can be useful, such as:

A

IgG assays (tTG IgG) OR upper endoscopy with Bx.

68
Q

Celiac disease - Dx and evaluation - Bx:

A

In SOME cases, the diagnosis of celiac disease requires a small-bowel Bx, which demonstrates flattened or blunted villi + INCREASED LYMPHOCYTES.

69
Q

Celiac disease - Dx and evaluation - Gold standard for confirmation of diagnosis:

A

Repeat endoscopy with biopsies after initiating a strict gluten-free diet.

70
Q

Most relapses in celiac disease are from …?

A

Dietary noncompliance or hidden sources of gluten.

71
Q

REFRACTORY celiac disease:

A
  1. May require steroids or other immunosuppressives.

2. The possibility of early-onset small-bowel lymphoma should be considered in refractory cases.

72
Q

Celiac disease - Response to treatment:

A
  1. Monitored with antibody testing, either IgA tTG antibody or IgA antigliadin antibody.
  2. If dietary adherence is present, the antibodies should return to normal within 3-12 months after initiation of gluten-free diet.
73
Q

Celiac disease - Nutritional deficiencies:

A

Iron, Ca, Ph, folate, B12, ADEK should be identified and treated.

74
Q

Tropical sprue (rare outside tropical areas):

A

Chronic diarrhea and malabsorption after traveling to or living in a tropical area.

75
Q

Tropical sprue - Most patients have evidence of …?

A

FOLATE DEF.

76
Q

Tropical sprue - Infectious agents implicated?

A

Klebsiella.

77
Q

Tropical sprue - Pathology:

A

Similar to celiac sprue, but no response to gluten-free diet.

78
Q

Tropical sprue - Tx:

A

Tetracycline + folate.

79
Q

Whipple disease - Target group:

A

Middle-aged men.

80
Q

Whipple disease - Etiology:

A

Gram (+) bacillus = Trophyrema whippelii.

81
Q

Whipple disease - Presentation:

A
  1. Diarrhea.
  2. Steatorrhea.
  3. Abdominal pain.
  4. Weight loss.
  5. Migratory arthritis.
  6. Fever.
82
Q

Whipple disease - Neurologic:

A
  1. Dementia.
  2. Ocular disturbances.
  3. Meningoencephalitis.
  4. Cerebellar symptoms.
83
Q

Whipple disease - Cardiac:

A
  1. CHF.
  2. Pericarditis.
  3. Valvular heart disease.
84
Q

Whipple - Dx:

A
  1. PAS-positive macrophages usually in small bowel.

2. Antibodies to the protein and PCR to the DNA of trophyrema whippelii can also help to establish the diagnosis.

85
Q

Whipple disease - Tx:

A

1 YEAR TMP-SMX.

86
Q

Bacterial overgrowth syndrome - Etiology:

A
  1. Small-bowel stasis.
  2. Abnormal communication between the small-bowel and colon.
  3. Multifactorial.
87
Q

Bacterial overgrowth syndrome - Small bowel stasis:

A
  1. Anatomic abnormalities ==> post-surgical anatomy, diverticulae.
  2. Abnormal small bowel motility ==> Scleroderma, DM.
88
Q

Bacterial overgrowth syndrome - Abnormal communication:

A

Crohn or resection of the ileocecal valve.

89
Q

Bacterial overgrowth syndrome - Multifactorial:

A
  1. Chronic pancreatitis.
  2. Cirrhosis.
  3. Achlorhydria.
  4. Immunodeficiency.
90
Q

Bacterial overgrowth syndrome - Clinical presentation:

A
  1. Bloating, flatulence, abdominal pain.
  2. Diarrhea.
  3. Steatorrhea is caused by impaired micelle formation because of bacterial DECONJUGATION of bile acids in the proximal small bowel.
  4. Weight loss.
  5. Dermatitis, arthritis.
  6. Vitamin deficiencies ==> B12 (common), A, D.
  7. FOLATE may be ELEVATED because it is produced by enteric bacteria.
91
Q

Bacterial overgrowth syndrome - Dx - Gold standard:

A

Small-bowel aspirate demonstrating bacterial overgrowth (greater than 10^5 CFUs), but aspirate is difficult to perform well, costly, and not widely available.

==> NOT required in most cases.

92
Q

Bacterial overgrowth syndrome - Dx - Breath test:

A

Can be performed more readily at less cost, but the validity of the results is controversial.

==> Testing has a high FALSE-POSITIVE rate.

93
Q

Bacterial overgrowth syndrome - Dx - Other breath tests:

A
  1. Glucose breath testing.
  2. Lactulose: hydrogen breath test.
  3. 14C-glycocholate breath test: infrequently available or performed.
  4. 14C-D-xylose breath test.
94
Q

Bacterial overgrowth syndrome - Dx - Normalization of Schilling test:

A

AFTER abx is HIGHLY SUGGESTIVE OF bacterial overgrowth.

95
Q

Bacterial overgrowth syndrome - Tx:

A
  1. Destroy the overgrowth.
  2. Eliminate the underlying cause when feasible.
  3. Improve gut motility.
  4. Eliminate nutritional deficiencies with supplementation.
96
Q

Bacterial overgrowth syndrome - Tx - Destroy the overgrowth:

A
  1. Broad-spectrum abx can be used for several weeks. Sometimes cycling of abx or recurrent courses are needed.
  2. NON absorbable options: rifaximin, neomycin.
  3. Absorbable options: ciprofloxacin, tetracycline, metronidazole.
97
Q

Bacterial overgrowth syndrome - Tx - Eliminate the underlying cause, when feasible:

A

Some patients require surgery (eg small-bowel diverticulosis).

98
Q

Bacterial overgrowth syndrome - Tx - Improve gut motility:

A

If slow transit is noted, improving rate of transit can help.

99
Q

Bile acid malabsorption:

A

Bile acids are absorbed in the ileum.

==> Diseases that affect the ileum (ie Crohn disease) or where the ileum has been resected can contribute to bile acid diarrhea.

100
Q

Bile acid malabsorption - 2 basic types of the disease:

A
  1. Bile acid diarrhea.

2. Fatty acid diarrhea.

101
Q

Bile acid malabsorption - Bile acid diarrhea:

A
  1. Associated with limited ileal abnormality or resection.
  2. Impaired bile acid absorption in the ileum leads to chloride and water secretion in the colon.
  3. Steatorrhea does NOT develop because the liver is able to compensate for the loss of bile acids in the stool.
  4. Responds to cholestyramine.
102
Q

Bile acid malabsorption - Fatty acid diarrhea:

A
  1. Associated with extensive ileal abnormality/resection.
  2. Liver is unable to compensate for the loss of bile acids in the stool, so steatorrhea develops.
  3. Does NOT respond to cholestyramine.
  4. May respond to low-fat diet.
103
Q

Microscopic colitis - Epidemiology:

A
  1. Patients in their 50s and 60s.

2. 10% of chronic diarrheas.

104
Q

Microscopic colitis - 2 types:

A
  1. Collagenous colitis ==> More freq in women.

2. Lymphocytic colitis ==> More common.

105
Q

Microscopic colitis - Associated with CERTAIN DRUGS:

A
  1. NSAIDs.
  2. Ticlopidine.
  3. Olmesartan.
  4. Ranitidine.
  5. Lansoprazole.
    + others.
106
Q

Microscopic colitis is associated with other diseases, especially:

A

CELIAC DISEASE.

107
Q

Microscopic colitis - When to consider?

A

In the DDx of patient with celiac disease adhering to a strict diet but who continues to have symptoms.

108
Q

Microscopic colitis - Clinical presentation:

A
  1. Microcytic anemia.
  2. Diarrhea.
  3. Weigth loss.
  4. Abdominal discomfort.
  5. Fatigue.
109
Q

Microscopic colitis - Dx and evaluation:

A

Made by histologic examination.

110
Q

Microscopic colitis - Dx and evaluation - Histologic criteria for diagnosing microscopic colitis:

A
  1. Incr. chronic inflammatory infiltrate in the lamina propria.
  2. Incr. number of intraepithelial lymphocytes (more than 15-20 lymphocytes per 1000 epithelial cells).
  3. Damage of the surface epithelium with flattening of the epithelial cells.
111
Q

Microscopic colitis - Dx and evaluation - The presence of SUBEPITHELIAL COLLAGENOUS band is …?

A

PATHOGNOMONIC OF COLLAGENOUS COLITIS, and differentiates it from lymphocytic colitis, which lacks such a band.

112
Q

Microscopic colitis - Tx:

A

Microscopic colitis can resolve spontaneously if there is an inciting factor that is identified and removed.

==> STOP NSAIDs or associated drugs.

113
Q

Microscopic colitis - Tx - Most patients require specific therapy:

A
  1. 1st line ==> Budesonide.
  2. Other choices ==> 5-ASA like mesalamine or sulfasalazine, bismuth, prednisone, and rarely, strong immune-suppressive agents or biologics.
114
Q

Microscopic colitis - Tx - Symptoms of diarrhea may respond to …?

A

CHOLESTYRAMINE.

Decks in ► Med - Internal Medicine Class (101):