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Flashcards in Small bowel and appendix Deck (30)
1

Tumors of the appendix

Very rare (0.9% of apply specimens)

Carcinoid: 0.5% appendectomy specimens (Neuroendocrine tumor)
Metastasis rare if tumor

2

Malabsorption/Maldigestion

Syndrome of disordered or inadequate absorption of nutrients
Clinical signs: weight loss, diarrhea, steatorrhea, vitamin deficiencies
Pale, bulky, malodorous stool
Float, difficult to flush
Oily residue

Causes: surgery, bacterial overgrowth, medications, pancreatic insufficiency, liver disease, intestinal inflammation, ulceration, ischemia, infiltration

3

Pancreatic Insufficiency

Digestive enzymes: Lipase, Trypsin etc
90% of pancreas burned out
Lipid maldigestion first
Protein malabsorption
Carbohydrate malabsorption rare
Chronic pancreatitis
Cystic fibrosis

4

Liver Disease

Can cause malabsorption

Bile necessary for the absorption of lipids
Cirrhosis
Decreased function of hepatocytes
Decreased bile formation
Biliary Obstruction

5

Gastric bypass

malabsorption by design

B12, Fe, Ca, Vit D deficiencies the most common
Vitamin C, Cu rare
Prevention: Multivitamin
Monitoring Recommended

6

Small Bowel Bacterial Overgrowth (normal number of organisms/ml, causes, and clinical signs)

Normal bacteria: (

7

Tests for small bowel bacterial overgrowth and treatment

Fat soluble vitamin and B12 deficiency
Bacteria de-conjugate bile salts
Bacteria consume B12

Folate levels will be normal to high
Bacterial production

Diagnosis:
Aspiration of duodenum with culture
Glucose-Hydrogen breath test
Empiric Treatment with Antibiotics

Treatment: Antibiotics (e.g. Ciprofloxacin)

8

Celiac sprue

Gluten-sensitive enteropathy
Wheat, barley, rye
Inflammatory disease of small intestine
Loss of villi, crypt hyperplasia, IE Lymphocytes
0.5-1.0% of US population
80% asymptomatic
Incidence increases with age

9

Typical Celiac Sprue Signs and Symptoms

Abdominal distension
Abdominal pain
Anorexia
Bulky, sticky, pale stools
Steatorrhea
Diarrhea
Flatulence
Failure to thrive
Weight loss
Fatigue
Vomiting

10

Atypical Celiac Sprue Signs and Symptoms

Iron deficiency Anemia
Dermatitis Herpetiformis
Liver function tests
AST, ALT elevations
Cerebellar ataxia
Osteoporosis
Oral apthous ulcers

11

Celiac Pathogenesis

Associated with autoimmune diseases
e. g. Thyroiditis, Type-I diabetes

Female:Male=2:1

HLA-DQ2, HLA-DQ8 (40% US)
APC-MHC-II, present gluten peptides
2-5% gene carriers develop disease
Other genes + environment

CD4+ T cell response (IELs)

All have antibodies to tissue transglutaminase

12

Celiac sprue diagnosis and treatment

Diagnosis: findings on small intestine biopsy

Serologic Tests: anti-tissue transglutaminases, anti-endomysial antibodies, anti-gliadin IgA and IgG

Treatment: Gluten free diet

Future: Wheat without gluten epitopes, degradation of epitopes, oral tolerance, hookworms..

13

Tropical sprue

Residents or visitors to tropics

Cause: bacterial toxins or colonization of aerobic coliform bacteria

Classic presentation: Megaloblastic anemia from B12 and folate deficiency

Diagnosis: intestinal biopsy with villous flattening and travel history

Treatment: Antibiotics, B12, and folate

14

Whipple's disease (epidemiology, cause, signs, diagnosis, and treatment)

Rare:

15

Mesenteric Ischemia

Atherosclerosis, Clot, Radiation

Chronic: 2 of 3 major vessels occluded
post-prandial abdominal pain, weight loss, sitophobia, malabsorption

Acute: embolus, severe abdominal pain

16

Malabsorption diagnostic tests

Focused testing-clinical scenario
Fecal Fat
Vitamin levels
CBC, albumin
CT-small bowel, liver, pancreas, bile ducts
Endoscopy

17

Small Intestinal Tumors

Very rare cause of primary tumors (despite 90% of gut surface area)

18

Two main causes of diarrhea

1. Decreased absorption of fluid and electrolytes
2. Increased secretion of fluid and electrolytes

19

Classification Of Diarrhea Based On Stool Characteristics

Fatty
Malabsorption
Maldigestion
Watery
Osmotic
Secretory
Inflammatory/Exudative
Blood
Functional

20

Watery Diarrhea--Osmotic

Carbohydrate malabsorption
-Lactose
-Sorbitol (chewing gum)
-Fructose (non-diet drinks and many commercial foods—high fructose corn syrup)
Osmotic laxatives
-Magnesium-containing
-Phosphate, sulfate (colonoscopy bowel preps)

21

How can you tell the difference between Osmotic and Secretory Diarrhea

Measure stool sodium + potassium

The normal stool osmolality is 290 mOsm
Osm gap =290-2(stool sodium + potassium)

If the difference is > 50 mOsm, then the diarrhea is osmotic; if

22

Lactose intolerance

Down-regulation of lactase after weaning

Lactose ingestion leads to diarrhea (osmotic), flatulence (colonic bacteria)

Mutations in lactase promoter result in lactase persistence in ~80% Northern European and nomadic populations

23

Causes of Watery Diarrhea--Secretory

Bacterial toxins
-V. cholerae, E. coli enterotoxins

Neuroendocrine tumors (rare)
-gastrinoma, VIPoma, carcinoids, calcitonin

Ileal bile salt malabsorption

Stimulant laxatives

Disordered motility/regulation
-Diabetic neuropathy, postvagotomy, irritable bowel syndrome

24

Bile-acid induced diarrhea

bile salts stimulate colon and can cause diarrhea

25

Causes of fatty diarrhea

Malabsorption syndromes
-Mucosal diseases (Celiac disease, Whipple’s disease)
-Short-bowel syndrome
-Small bowel bacterial overgrowth
Maldigestion/Malabsorption
-Pancreatic insufficiency
-Inadequate luminal bile salt concentration (chronic liver disease, biliary obstruction)

26

Causes of Inflammatory Diarrhea

Infection
Inflammatory Bowel Disease
Crohn’s Disease
Ulcerative Colitis
Ischemia

27

How to test for fatty diarrhea

Sudan fat stain
Have pt eat high fat meal before

28

Inflammatory Diarrhea Diagnosis

Infection: Usually Stool Culture; Endoscopy

Ischemia: CT scan; Endoscopy-colon

Inflammatory Bowel Disease: Endoscopy

29

Irritable Bowel Syndrome (IBS): characteristics

Abdominal Pain and altered bowel habits in the absence of an organic cause

Pain improved with defecation

Pain onset with change in stool frequency

Pain onset with change in stool appearance

Constipation and/or Diarrhea

10-15% of the population North America

30

Possible mechanisms of IBS

Visceral hypersensitivity

Carbohydrate malabsorption (consider FODMAPS diet)

Low grade inflammation