B5-036 CBCL: Constipation Flashcards
Rome IV criteria for functional constipation
8
- straining in 25% of defecations
- lumpy or hard stools 25% of the time
- sensation of incomplete evacuation 25% of the time
- sensation of anorectal obstruction/blockage 25% of time
- manual maneuvers to facilitate more than 25% of defecations
- fewer than 3 SBM/week
- loose stools rarely present without use of laxatives
- insufficient criteria for IBS
must have two or more
Rome IV for opiod induced constipation
- straining in >25% of defecations
- lumpy, hard stools >25% of defecations
- sensation of incomplete evacuation >25% of defecations
- sensation of anorectal obstruction/blockage in >25% of defecations
- manual maneuvers to facilitate more than 25% of defecations
- fewer than 3 SBM/week
two or more of the above, new or worsening with opiod therapy
Rome IV for IBS
- Abdominal pain at least 1 day per month over at least 3 months associated with one or more of the following:
- Related to defecation
- A change in frequency of stool
- A change in form (appearance) of stool
Symptom onset should occur 6 months before diagnosis and symptoms should be present within past three months.
must have all
for IBS diagnosis, criteria need to occur for at lease
length of time
3 months
stimulant laxatives act by
stimulating enteric nerves to induce peristalsis
activating enteric mu receptors is a mechanism of what drug class?
antidiarrheal
loperamid, difenoxin, diphenooylate, etc
mu agonists are selective for […] opiod receptors
intestinal
decrease parasympathetic drive and inhibit ACh release resulting in decreased motility
what drug class
anti-diarrheals
(mu agonists)
dietary supplements that add bulk and hold water to expand intestinal contents
what drug class
bulk forming laxatives
constipation is [more or less] common in the elderly
more
what receptor is responsible for mediating opiod induced constipation?
mu opioid receptor
what neurotransmitter is used to induce smooth muscle cell contraction during peristalsis?
ACh
what is the consequence of chloride secretion into the lumen?
water is drawn into intestinal lumen
what neurotransmitters relax the receiving segment of the intestine distal to the bolus?
NO, VIP
what transporter maintains cellular Cl- concentrations?
basolateral Na/K/Cl transporter
Na and water are drawn into the lumen through the paracellular pathway by
lumen negative transepithelial voltage
psychosocial disturbances are associated with
IBS
associated with psychiatric stress, sleep disturbance, affective culnerability, and over adjustment to environment
IBS
gastrocolin and duodenocolic reflexes intiate […], moving fecal matter to rectum
power propulsions
rectoanal reflex relaxes the
internal anal spinchter
the voluntary decision to defecate results in the relaxation of
2
puborectalis muscle
external anal sphinchter
the colon is sacculated in small pouches called
haustra
motor patterns with the haustra are involved in
mixing and stool formation
decreased effectiveness of medicine over time
tolerance
abberant behavioral response that is characterized by craving a substance, obsessive thinking and poor inhibitory control relating to a substance
addiction
clinical phenomenon associated with chronic low mood, vegetative symptoms, and mild cognitive dysfunction
depression
intentional or accidental misuse of a substance
substance abuse
clinical phenomena associated with negative and intrusive thinking and physiological arousal
anxiety
predicatable responses associated with opioids that affect most patients
2
tolerance and dependence
risk factors associate with an increased risk of addication
2
hx of depression
hx of substance abuse
common adverse effect of aluminum antacids
constipation
common adverse effects of magnesium antacids
diarrhea
dry mouth can be a side effect of [….] as they can limit acid secretion
anti cholinergic
when given orally, has extensive first pass metabolism and can reduced OIC
naloxone
mu selective antagonist incapable of crossing the blood brain barrier
methylnatrexone
side effects of iron supplement
2
constipation
darken stool
magnesium salts cause
diarrhea
pain with defecating is more consistent with what diagnosis?
IBS
fewer than […] bowel movements per week is criteria for functional constipation
3
pain during defecation
change in stool
IBS
for constipation to be attributed to opioid use, what criteria must be met
new or worsening constipation after initiating, changing or increasing opiod use
what is the mechanism of OIC?
hypolarization by activating K+ channels
causes decreased release of neurotransmitters involved in peristalsis
opioids cause hyperpolarization via activation of […] channels
potassium
adenylate cyclase is […] with opioid use
increased or decreased
decreased
opioid use […] Ca channels
inhibits or upregulates
inhibits
opioid inhibition of VIP and ACh results in
less intestinal secretions
slow intestinal transit time allowing for greater absorption of water
opioids
activation of CFTR results in […] secretions
increased or decreased
increased
opioids can diminish the perception of sensation for urgency for defecation by
increasing the threshold for pain
opioids increase the threshold for pain sensation resulting in the decreased sensation for the
urgency to defecate
why do bulk forming laxatives + opioids cause abdominal distension?
opioids decrease perstalsis what cause a much lower transit time giving the bulk forming laxative more time to accumulate and distend the intestine
does not develop tolerance to opioids
GI tract
potential contributors to the development of IBS
4
- altered intestinal mobility
- altered microbiota
- disturbance of brain/gut function
- immune dysfunction
pathophysiologic changes causing constipation in the aging bowel
3
- depletion of interstitial cells of Cajal
- increased deposit of collagen in ascending colon
- slow transit constipation
PEG requires adequate
hydration
if a patient is not experiencing an adequate response to PEG, what is the initial advise?
drink more water
what do lubiprostone and linacoltide do?
increase water content of stool
stimulate secretion of chloride into the lumen resulting in the passive diffusion of Na+ and water
lubiprostone
stimulate secretion of chloride into the lumen resulting in the passive diffusion bicarb and water
lubiprostone
