W4L3 Diarrhea

Question 1

Def

Answer 1

1. Symptomatic def:
   - Inc frequency, fluidity, vol, or combine
2. Physiologic def:
   - Dec abs/Inc secretion, or both, coz >200mL liquid excretion(300g)/d

Question 2

Class?

Answer 2

1. Acute vs Chronic
2. Infectious vs Non-infectious
3. Osmotic vs Secretory
4. Inflammatory vs Non-inflammatory
5. Large intestine vs Small intestine
6. Drug induced

Question 3

Acute vs. Chronic?

Answer 3

Acute diarrhea:

• Inf -Iatrogenic -Toxin
• Diet -Nervous

Chronic diarrhea:(>2w)

• Malabs syn coz
• Colonic coz -Endocrinal co

Question 4

Osmotic vs Secretory?

Answer 4

Osmotic diarrhea:

• Non abs solutes(Lactulose)→ ↑ intraluminal oncotic pressure→ out pour h2o
• Improve by fasting.
• Stool osmotic gap >50mOsm/kg

Secretory diarrhea:

• Active ion secretion→ obligatory water loss & ↑ stool Na & K
• Coz viral inf, HIV asso, vipoma, carcinoid.
• Stool osmotic gap <50mOsm/kg
• Xaff by fasting

Question 5

Inflammatory vs Non-inflammatory?

Answer 5

Inflammatory
-Frequent, bl, pus, fever, abd pain, tenesmus, fecal leukocyte

Non-inflammatory
-Watery stool, wo blood/pus/fever/fecal leukocytes

Question 6

Infectious vs Non-infectious

Answer 6

Infectious
-Fever, bl, pus, epidemic, travel

Less likely infectious
-Afebrile, non-bl, non-mucoid, sporadic, no travel

Question 7

Large Intestine vs Small Intestine

Answer 7

Large intestine
-Frequent urge, dark colored/rarely foul, lt LQ pain, tenesmus, small volume

Small intestine
-Watery/light colored/foul, periumbilical /RLQ pain, large volume

Question 8

Small Volume vs Large Volume

Answer 8

Small Volume(<400ml)
-Rectal & sigmoid dis(UC, ulcerative proctitis)

Large Volume(>400ml)

• Osmotic(Lactase deficiency)
• Secretory(Cholera, laxatives)
• Dysmotility(Postgastrectomy syn, carcinoid) -Altered permeability(Sprue)

Question 9

Drug-Induced Diarrhea

Answer 9

Temporal relation to diarrhea

-Acarbose, Antibiotic & Metformin

Question 10

Evaluation

Answer 10

1. Acute diarrhea:
   - Evaluate when dehy, febrile/bl/pus in stool.
2. Chronic diarrhea:
   - Evaluate when >2w

Question 11

Initial evaluation of Chronic Diarrhea

Answer 11

1. History
2. Physical examination
3. Routine laboratory tests
4. Analysis of stool sample

Question 12

History

Answer 12

1. Age
2. Duration of symp
3. Severity diarrhea
4. Drugs, coincidence w onset diarrhea
5. Aggravating & relieving factor
6. Review pt diet
7. Surgery/radiation
8. Stool characteristic

Question 13

Physical Examination

Answer 13

1. Determine severity diarrhea
   - Vol status(bp & pulse, dehy)
   - Fever & other signs toxicity
   - Abd exam(bowel sound, abd distention, tender, mass, enlarged liver)
2. Characteristic skin change in:
   - Addison’s dis, Carcinoid syn
   - Tremor & other sys sign
   - Arthritis -Lymphadenopathy

Question 14

Inv

Answer 14

1. Lab
   - CBC, s electrolyte, Ca, albumin, PT time, Urea, Cr & ESR
2. Stool exam
   - Random sample -Collected sample
   - Osmotic gap
3. Other studies
   - D-Xylose abs test -14C xylose
   - Test small bowel abs capacity
   - Test bact over growth
4. Measure stool Na & K
   - Osmotic gap = 290 mOsm/Kg - 2 (Na + K)
5. Culture for bacterial pathogens

Question 15

Treatment

Answer 15

• Treat etiology
• Rehyd therapy(IV-Oral)
• Electrolyte replacement
• Bind osmotically active substance (kaolin & pectin)
• Opiate ↓ intestinal motility(lopramide & diphenoxylte)(ci in inf diarrhea)