Functional Gastrointestinal Disorders Flashcards
What is functional dyspepsia?
A collection of disease so it is lumped into functional GI disease
What are childhood physical or sexual trauma typically implications in?
Adult IBS
Rome III diagnostic criteria for irritable bowel syndrome:
- ) Abdominal pain or discomfort accompanied by at least two of the following symptoms 25% of the time
- ) No evidence of an inflammatory, anatomic, metabolic, or neoplastic process explaining the symptoms
What are the symptoms in Rome III diagnostic:
A.) Improvement with defecation
B.) Onset associated with change in stool frequency
C.) Onset associated with change in appearance of stool
What is IBS characterized as?
Biopsychosocial disease
What percent of IBS patients are thought to have been sexually abused?
32%
In IBS what occurs to gastrointestinal motility?
Increased activity for 3 hrs after eat
IBS-D bile secretion:
Increased bile secretion
What is one possible feedback mechanism dysfunction in IBS?
Bile enter enterocytes (IBAT), presence of bile binds to Farnesoid-gamma nuclear receptors releasing FGF-19, FGF-19 bind FGFR4 inhibiting bile synthesis (this goes wrong)
What does bile in feces cause?
Stimulates motility
What are three possible genetic defects to cause excess bile?
FGFR4 gene variant
Beta klotho gene variant
GPBAR1 gene variant
What is beta klotho?
Enzyme
What is GPBAR1 gene?
When active it suppresses 7 alpha-hydroxylase decreasing bile synthesis
What is SHP?
Regulates transport mechanism, when activated it shuts down ASBT so that bile cannot be absorbed into the enterocytes
How does bile cause IBS symptoms?
Binds and activates GPBAR1 on enteroendocrine cells, enteric neurons, and visceral afferents inducing motor, sensory and secretory effects
How can short chain fatty acids generated IBS symptoms?
SCFA generated by microbiome, activate free fatty acid receptor on I-cells releasing CCK binds to vagal nerves causing bloat feel and binds mast cells releasing serotonin to neurons triggering motility
How can post infectious IBS occur?
Mucosal permeability due to infection allowing membranes to be permeable causing leakage of bacterial products
Which IBS is bacterial overgrowth possible?
IBS-C (lactobacillus and collinsella decreased)
What bacteria cause post infectious IBS?
Campylobacter
Salmonella
Shigella
Why does stress cause IBS?
Release of proinflammatory cytokines
What occurs with inflammation to the myenteric neurons?
Chronic changes in neuron action potentials
What drugs can be used to treat IBS?
Alosetron: IBS-D
Lubiprosterone: IBS-C
What does Alosetron inhibit?
Serotonin signals (5-HT3 antagonist)
What does Lubiprostone do?
Promotes secretion through chloride channels
