Diarrhea & Constipation

Question 1

normal colonic function

Answer 1

~1L/day of undigested residue thru colon

• -func = convert liquid effluent into semi-solid feces
• -output = ~200g of stool & 60-80% water

Question 2

physiological process involved in solidifying the liquid effluent

Answer 2

• -absorption of fluid & electrolytes
• -peristaltic contractions
• -under the control of a complex enteric nervous system
• -defecation

Question 3

absorption of fluid & electrolytes

Answer 3

• -Na+ & Cl- actively transported primarily in the ascending & transverse colon
• -water is passively reabsored with these electrolytes

Question 4

peristaltic contractions

Answer 4

facilitate mixing, desiccation, and passage

Question 5

under the control of a complex enteric nervous system

Answer 5

• -sensitive to a variety of pharmacological agents

- -detailed drug Hx is essential when eval constipation or diarrhea

Question 6

defecation

Answer 6

• -defecatory reflex initiated by distention of the rectum
• -sigmoidal & rectal contractions
• -relaxation of the internal & external anal sphincters
• -voluntary increased intra-abdominal pressure

Question 7

when the ability to resist the defecatory urge is over-utilized…

Answer 7

chronic rectal distention
reduced afferent signals
lax tone
chronic constipation may result

Question 8

Secretory Diarrhea

Answer 8

clear non-cellular feces w. fluid rich in electrolytes due to excessive secretion or impaired absorption
**Cholera

Question 9

Osmotic diarrhea

Answer 9

clear non-cellular feces due to decreased water reabsorption due to increased levels of non-absorbable molecules

• *Lactase deficiency
• *Mg+2 containing cathartics

Question 10

Exudative diarrhea

Answer 10

purlulent, PMN laden, often bloody feces from an outpouring of necrotic mucosa & electrolytes resulting from an inflamed colon

• *Ulcerative colitis
• *Shigellosis
• *Amebiasis

Question 11

anatomic derangement diarrhea

Answer 11

Decreased absorption surface

**subtotal colectomy

Question 12

motility disorder diarrhea

Answer 12

Decreased contact time upon colonic mucosa

• *Hyperthyroidism
• *IBS

Question 13

general considerations about infection induced acute diarrhea

Answer 13

abrupt onset in healthy person = bacteria, virus, protozoa

SYMPTOMS = fever, HA, anorexia, vomiting, malaise, myalgia

Question 14

Bacterial diarrhea

Answer 14

• -assoc w/ other individuals have simultaneous illness
• -diarrhea ~12 h after ingestion of exotoxin (Staph)
• -diarrhea ~3day lag time = food had multiple orgnaisms (Salmonella, Shigella, Campylobacter)
• -often causes exudative diarrhea (life-threatening d/t massive electrolyte loss

Question 15

Viral diarrhea

Answer 15

• -Dx when bacteria/protozoa cannot be found in stool
• • ~1-3days
• -rarely life threatening not exudative

Question 16

Protozoal diarrhea

Answer 16

• -Entamoeba histolytica common in USA

- -Giardiasis via drinking contaminated water

Question 17

non-infectious induced acute diarrhea

Answer 17

• -inflammatory bowel disease: Crohn’s & U.C.
• -Diverticulitis
• -Drugs: cholinergic agents, Mg2+ antacids, anti-metabolites, anti-biotics

Question 18

Dx approach in acute diarrhea

[highly individualized]

Answer 18

Hx –> Frequency, Volume, Appearance, Odor, Presence or absence of fecal incontinence
Lab –> stool analysis, culture, ova & parasite, testing for occult blood

Question 19

what are looking for in appearance of a stool

Answer 19

• -presence or absence of blood
• -oiliness or greasiness
• -consistency

Question 20

chronic diarrhea

Answer 20

–diarrhea for weeks or months may = serious illness

Question 21

chronic diarrhea + palpatory abdominal tenderness & fever indicating inflammation

Answer 21

• -U.C.
• -Crohn’s
• -Amebiasis
• -Diverticulitis

Question 22

chronic diarrhea + no signs of inflammation = malabsorptive syndrome

Answer 22

accompanied by various: weight loss, malodorous stools, abdominal distension, anemia
Common causes:
–Sprue
–Pancreatic insufficiency
–Bacterial overgrowth secondary to decreased peristalsis
–endocrine disorders
–Habitual use of cathartics

Question 23

Bacterial overgrowth secondary to decreased peristalsis involve:

Answer 23

• -scleroderma

- -diabetic visceral neuropathy

Question 24

endocrine disorders involve:

Answer 24

• -thyrotoxicosis
• -diabetes mellitus
• -adrenal insufficiency
• -hypoparathyroidism

Question 25

description of a constipated stool

Answer 25

• -infrequent
• -incomplete
• -hard
• -need to strain for complete defecation
• -do not need to go every day

Question 26

constipation + organic illness =

Answer 26

• -spinal cord injury
• -systemic sclerosis
• -hirschsprung’s disease

Question 27

constipation + non-organic problem

Answer 27

• -depression
• -medications
• -conditions w/ painful defecation [hemorrhoids, anal fissures, perianal abscesses]

Question 28

nature of the patient (adult)

Answer 28

–review pt bowel habits ~ = easily correctable cause
+ water intake
+ roughage in diet (& reduce refined carbs)
+ daily exercise
+ time for a bowel movement (do not suppress urge)

Question 29

nature of the patient (kid)

Answer 29

–constipation in neonates = rare
–constipation in childhood =
MC d.t change in daily routine
Often component of toilet training
Consider painful defecation