Intro, Vomiting, Diarrhea, Clinical Approach

Question 1

What are the 3 functions of the stomach?

Answer 1

1. Filling
2. Mixing
3. Emptying

Question 2

What are components of the gastric mucosal barrier? What happens when this is damaged?

Answer 2

Purpose: Prevents stomach from digesting itself

Components: 1) surface mucous 2) bicarb 3) epithelial cells 4) blood flow 5) prostaglandins and cytoprotection 6) basal membrane

When it is damaged:

Back diffusion of H+ ions -> histamine release -> edema -> damage to capillaries -> erosions and ulcerations (with pain, nausea, vomiting)

Question 3

What stimulates the emetic center in vomiting?

Answer 3

1. Cerebral cortex (anxiety, anticipation)
2. Chemoreceptor trigger zone (apomorphine, toxins, etc.)
3. Oculo-vestibular system (motion)

Question 4

What are the three phases of vomiting?

Answer 4

Nausea
Retching
Vomiting

Question 5

How is intestinal fluid secreted and absorbed?

Answer 5

Water in GI comes from intake + secretions within GI tract associated with normal digestion
Most of this is absorbed back (duodenum, jejunum > ileum > colon)
Colon is most efficient at reabsorbing water
Villi: increased GI surface area! (Jejunum + ileum)

Question 6

What are the main types of diarrhea?

Answer 6

Osmotic
Secretory
Exudative
Disordered motility
Mixed (MOST COMMON)

Question 7

What is osmotic diarrhea?

Answer 7

Excess of osmotically-active molecules in bowel
Results in failure to digest or absorb nutrients
Examples: EPI, intestinal dysbiosis, parvo, corona, rotavirus

Question 8

What is secretory diarrhea?

Answer 8

Secretion > absorption
Often persists despite fasting
Example: E. coli, fat malabsorption (EPI)

Question 9

What is exudative diarrhea?

Answer 9

Increased mucosal permeability that leads to leakage of fluid, serum protein, blood
Examples: hookworms, lymphangectasia, decreased oncotic pressure (hypoalbuminemia) and increased hydrostatic pressure (R sided cHF, portal hypertension)

Question 10

What is disordered motility?

Answer 10

Increased transit time = decreased absorption

Use antidiarrheal agents that slow GI motility

Question 11

What are the 14 signs of GI disease?

Answer 11

Vomiting
Regurgitation
Diarrhea
Abdominal pain
Tenesmus
Dyschezia
Hematochezia
Constipation
Flatus
Salivation
Shock
Weight loss
Anemia
Change in appetite

Question 12

What’s the difference between vomiting and regurgitation?

Answer 12

Vomiting:
Abdominal contractions, retching
Premonitory signs present
Ptyalism, pacing, swallowing, tachycardia (nausea)

Regurgitation: 
Effortless expulsion
Few premonitory signs
Ptyalism in esophageal inflammatory or obstructive disease
Rarely bile-stained

Question 13

What are the 5 mechanisms of weight loss?

Answer 13

1. Drecreased nutrient intake
2. Maldigestion/malabsorption
3. Malassimilation
4. Excessive utilization
5. Increased loss of nutrients

Question 14

What diagnostics are helpful in diagnosing GI disease?

Answer 14

Lab work - hemogram, chem, urinalysis, fecal

“Confirmatory tests” - cPLI, fPLI, TLI, folate, cobalamine, fecal alpha proteinase inhibitor