Diarrhea & Constipation Flashcards
normal colonic function
~1L/day of undigested residue thru colon
- -func = convert liquid effluent into semi-solid feces
- -output = ~200g of stool & 60-80% water
physiological process involved in solidifying the liquid effluent
- -absorption of fluid & electrolytes
- -peristaltic contractions
- -under the control of a complex enteric nervous system
- -defecation
absorption of fluid & electrolytes
- -Na+ & Cl- actively transported primarily in the ascending & transverse colon
- -water is passively reabsored with these electrolytes
peristaltic contractions
facilitate mixing, desiccation, and passage
under the control of a complex enteric nervous system
- -sensitive to a variety of pharmacological agents
- -detailed drug Hx is essential when eval constipation or diarrhea
defecation
- -defecatory reflex initiated by distention of the rectum
- -sigmoidal & rectal contractions
- -relaxation of the internal & external anal sphincters
- -voluntary increased intra-abdominal pressure
when the ability to resist the defecatory urge is over-utilized…
chronic rectal distention
reduced afferent signals
lax tone
chronic constipation may result
Secretory Diarrhea
clear non-cellular feces w. fluid rich in electrolytes due to excessive secretion or impaired absorption
**Cholera
Osmotic diarrhea
clear non-cellular feces due to decreased water reabsorption due to increased levels of non-absorbable molecules
- *Lactase deficiency
- *Mg+2 containing cathartics
Exudative diarrhea
purlulent, PMN laden, often bloody feces from an outpouring of necrotic mucosa & electrolytes resulting from an inflamed colon
- *Ulcerative colitis
- *Shigellosis
- *Amebiasis
anatomic derangement diarrhea
Decreased absorption surface
**subtotal colectomy
motility disorder diarrhea
Decreased contact time upon colonic mucosa
- *Hyperthyroidism
- *IBS
general considerations about infection induced acute diarrhea
abrupt onset in healthy person = bacteria, virus, protozoa
SYMPTOMS = fever, HA, anorexia, vomiting, malaise, myalgia
Bacterial diarrhea
- -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
Viral diarrhea
- -Dx when bacteria/protozoa cannot be found in stool
- ~1-3days
- -rarely life threatening not exudative
Protozoal diarrhea
- -Entamoeba histolytica common in USA
- -Giardiasis via drinking contaminated water
non-infectious induced acute diarrhea
- -inflammatory bowel disease: Crohn’s & U.C.
- -Diverticulitis
- -Drugs: cholinergic agents, Mg2+ antacids, anti-metabolites, anti-biotics
Dx approach in acute diarrhea
[highly individualized]
Hx –> Frequency, Volume, Appearance, Odor, Presence or absence of fecal incontinence
Lab –> stool analysis, culture, ova & parasite, testing for occult blood
what are looking for in appearance of a stool
- -presence or absence of blood
- -oiliness or greasiness
- -consistency
chronic diarrhea
–diarrhea for weeks or months may = serious illness
chronic diarrhea + palpatory abdominal tenderness & fever indicating inflammation
- -U.C.
- -Crohn’s
- -Amebiasis
- -Diverticulitis
chronic diarrhea + no signs of inflammation = malabsorptive syndrome
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
Bacterial overgrowth secondary to decreased peristalsis involve:
- -scleroderma
- -diabetic visceral neuropathy
endocrine disorders involve:
- -thyrotoxicosis
- -diabetes mellitus
- -adrenal insufficiency
- -hypoparathyroidism
description of a constipated stool
- -infrequent
- -incomplete
- -hard
- -need to strain for complete defecation
- -do not need to go every day
constipation + organic illness =
- -spinal cord injury
- -systemic sclerosis
- -hirschsprung’s disease
constipation + non-organic problem
- -depression
- -medications
- -conditions w/ painful defecation [hemorrhoids, anal fissures, perianal abscesses]
nature of the patient (adult)
–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)
nature of the patient (kid)
–constipation in neonates = rare
–constipation in childhood =
MC d.t change in daily routine
Often component of toilet training
Consider painful defecation
