Acute and Chronic diarrhea Flashcards
List underlying mechanisms associated with diarrhea
abnormal GI motor function
increased secretion
impaired absorption
inflammation
Describe the pathology in diarrhea due to abnormal motor function
increases in intraluminal fluid volume via increased secretion or decreased absorption stimulate propulsive activity, speed up transit with decreased contact leading to decreased absorption, and result in diarrhea.
List disorders that can impair intestinal motor function and lead to diarrhea
diabetes
hyperthyroidism
amyloidosis
scleroderma
How does diabetes lead to diarrhea?
autonomic neuropathy of enteric nervous system causes disorder of bowel motility
presents with watery diarrhea that is painless and worse at night
treatment: control blood sugars, loperamide, clonidine
How does hyperthyroidism lead to diarrhea?
intestinal hypermotility that reduces small bowel transit time, decreased contact, and decreased absorption of fluids
treatment is aimed at underlying thyroid disorder
How does amyloidosis lead to diarrhea?
autonomic neuropathy and infiltration of intestinal submucosa resulting in malabsorption, bacterial overgrowth
How does scleroderma cause diarrhea?
intestinal involvement of sclerosis leads to dysmotility from neuromyopathy, bacterial overgrowth, and malabsorption
List the underlying pathology of secretory diarrhea
secretion of water and electrolytes exceeds the absorption in the GI tract, which can result from increased secretion or decreased absorption
_____ diarrhea persists during fasting whereas _____ diarrhea stops when the patient fasts
Secretory diarrhea persists during fasting whereas osmotic diarrhea stops when the patient fasts
List causes of secretory diarrhea
Bacterial endotoxins: Vibrio cholerae, ETEC, S. aureus
Circulating secretagogues: VIPoma, Zollinger Ellison syndrome, serotonin
Luminal secretagogues: bile salts, laxative use
Decreased absorption due to surgical resection, microscopic colitis
What is the underlying pathology of osmotic diarrhea?
ingestion of poorly absorbable solutes such as sugars or divalent ions (e.g. magnesium or sulfate). These solutes cause net secretion of fluid and electrolytes due to osmotic gradients
List causes of osmotic diarrhea
- lactose intolerance
- celiac disease
- pancreatic insufficiency
How doe lactose intolerance lead to diarrhea?
osmotic diarrhea
Due to a primary lactase deficiency or a secondary deficiency such as with bacterial overgrowth or a recent gastroenteritis that results in villus flattening.
Describe how pancreatic insufficiency leads to diarrhea
Can result from disorders such as cystic fibrosis and chronic pancreatitis.
The stools are loose, greasy, and foul smelling due to excessive quantities of unabsorbed fat in the stool (steatorrhea).
Malabsorption of fat-soluble vitamins (A, D, E, and K) is a common long-term consequence.
Sugar substitutes or foods/ drinks high in fructose can cause _____ diarrhea
osmotic
