Constipation Week 5

Question 1

Constipation

Answer 1

is a common complaint in older adults & the most common digestive complaint in the general population

Question 2

Rome III criteria: functional constipation is defined as any two of the following features:

Answer 2

• straining - lumpy hard stools - sensation of incomplete evacuation - use of digital maneuvers - sensation of anorectal obstruction or blockage with 25 percent of bowel movements - decrease in stool frequency (less than three bowel movements per week)

Question 3

Rome III criteria requirements

Answer 3

need 2 of the features for the last 3 months with symptom onset 6 months prior to diagnosis

Question 4

in older adults constipation may be associated with what?

Answer 4

fecal impaction and fecal incontinence

Question 5

fecal impaction can cause

Answer 5

stercoral ulceration, bleeding, anemia

Question 6

Stercoral ulceration is ?

Answer 6

the loss of bowel integrity from the pressure effects of inspissated feces

Question 7

prevalence of constipation

Answer 7

prevalence of constipation in the older adult has not been well defined, but may be as high as 24- 50% of older adults, of whom 10- 18% use daily laxatives (especially community dwellings/ nursing homes)

Question 8

Constipation in the older adult- why?

Answer 8

Primary colorectal dysfunction or secondary to several etiologic factors (often multi- factorial in older adults)

Question 9

Primary colorectal dysfunction categorized into 3 broad sub- types:

Answer 9

slow transit constipation dyssynergic defecation irritable bowel syndrome

Question 10

slow transit constipation

Answer 10

• prolonged delay in stool transit throughout the colon - Possibly primary dysfunction of colonic smooth muscle: myopathy, neuronal innervation (neuropathy), secondary to dyssynergic defecation

Question 11

Dyssynergic defecation

Answer 11

• difficulty with or inability expelling stool from the anorectum - prolonged colonic transit time

Question 12

irritable bowel syndrome

Answer 12

• predominant constipation (IBS-C) is characterized by abdominal pain with altered bowel habits. - may or may not have slow colonic transit or dyssynergia - many have visceral hypersensitivity

Question 13

Constipation may be conceptually regarded as

Answer 13

disordered movement of stool through the colon or anorectum since, with few exceptions, transit through the proximal gastrointestinal tract is often normal. Slowing of colonic transit may be idiopathic or may be due to secondary causes.

Question 14

what kinds of drugs are associated with constipation?

Answer 14

• analgesics - anticholinergics (antihistamines, antispasmodics, antidepressants, antipsychotics) - cation- containing agents (iron supplements, aluminum ie. antacids, sucralfate, barium - neurally active agents (opiates, antihypertensives, ganglionic blockers, vinka alkaloids, calcium channel blockers, 5HT3 agonists)

Question 15

what receptor is at the root of this problem? (drugs causing constipation)

Answer 15

?? no idea

Question 16

alarm features of constipation

Answer 16

hematochezia, weight loss of ≥10 pounds, a family history of colon cancer or inflammatory bowel disease, anemia, positive fecal occult blood tests, or acute onset of constipation in elderly persons

Question 17

what can be considered when alarm features are absent?

Answer 17

empiric treatment (patient education, trial of dietary changes, and a trial of fiber) without diagnostic testing

Question 18

An important part of the history includes defining ? regarding constipation

Answer 18

the nature and duration of constipation. Can do 2 week bowel diary to make sure they are actually constipated and not just thinking they are- Reassurances regarding the broad range of normal bowel frequency may be all that is necessary in some cases.

Question 19

history should also focus upon

Answer 19

identifying secondary causes of constipation. (Most patients with idiopathic constipation are otherwise asymptomatic.)

Question 20

A recent and persistent change in bowel habits, if not associated with a readily definable cause of constipation (eg, medications) should

Answer 20

prompt an evaluation to exclude structural bowel changes or organic diseases, especially in older adults. A diagnosis of functional constipation should be considered only after these other diseases have been excluded.

Question 21

general physical examination is not helpful in most patients presenting with chronic constipation- instead what is useful? and why?

Answer 21

a rectal exam: - can identify fissures or hemorrhoids which may be caused by constipation, or which can be painful and thereby lead to voluntary stool retention and secondary constipation - A gaping or asymmetric anal opening may suggest that a neurologic disorder is impairing sphincter function - Responses of the puborectalis and external anal sphincter muscles may be evaluated by asking the patient to strain during the rectal examination; this is particularly useful in identifying patients with possible dyssynergic defecation

Question 22

Normal defection involves the:

Answer 22

coordinated relaxation of the puborectalis and external anal sphincter muscles, together with increased intraabdominal pressure and inhibition of colonic segmenting activity

Question 23

But in patients with dyssynergic defecation:

Answer 23

ineffective defecation is associated with a failure to relax, or inappropriate contraction of, the puborectalis and external anal sphincter muscles. This narrows the anorectal angle and increases the pressures of the anal canal so that evacuation is less effective. Relaxation of these muscles involves cortical inhibition of the spinal reflex during defecation; so, this pattern may represent a conscious or unconscious act.

Question 24

The pathogenesis of dyssynergic defecation

Answer 24

is not completely understood but is probably multifactorial. It is thought to be an acquired, learned dysfunction rather than an organic or neurogenic disease.

Question 25

DRE: examiner places the left hand on the patient’s abdomen to assess the push effort while the patient bears down, as if having a bowel movement. Normally- what happens?

Answer 25

the contraction of the abdominal muscles is accompanied by relaxation of the external anal sphincter and puborectalis muscles and perineal descent

Question 26

But in patients with dyssynergia

Answer 26

there may be an inability to contract the abdominal muscles, inability to relax the anal sphincter, paradoxical contraction of the anal sphincter, or the absence of perineal descent

Question 27

Work up for patients with red flags- (hematochezia, weight loss of ≥10 pounds, a family history of colon cancer or inflammatory bowel disease, anemia, or positive fecal occult blood tests, as well as a person with short-term history of constipation w/o obvious explanation)

Answer 27

Lab data- CBC, serum glucose, creatinine, calcium, and thyroid-stimulating hormone Radiography Endoscopy

Question 28

plain films of the abdomen can detect what?

Answer 28

significant stool retention in the colon and suggest the diagnosis of megacolon

Question 29

In patients without alarm symptoms or suspicion of organic disease, if the history and physical examination and a trial of conservative management do not reveal the cause of chronic constipation what should you do?

Answer 29

imaging study of the colon and rectum to exclude mass lesions, strictures, megacolon, and megarectum

Question 30

A normal imaging study should lead to evaluation of

Answer 30

colonic transit and pelvic floor dysfunction

Question 31

at least two of the following studies must be positive before diagnosing dyssynergic defecation

Answer 31

anorectal manometry; anal sphincter electromyography (EMG); defecography; and impaired balloon expulsion from the rectum

Question 32

Physiologic testing: Defecography

Answer 32

are specialized tests of colorectal function, generally reserved for patients with chronic constipation who do not respond to therapy with lifestyle/ dietary modifications and a trial of bulk forming and osmotic laxatives (**know these pics**)

Question 33

**Pics of abnormal defecogrpahy results

Answer 33

“You will see these again in a case study format/test question”

Question 34

interventions 1-4

Answer 34

1. lifestyle and dietary modification (fluid/ exercise)
2. bulk laxatives (if #1 fails)
3. a trial of osmotic laxatives (if #2 fails)
4. colon secretagogues (lubiprostone) should be considered only when #3 fails (stimulant laxatives are efficacious, but chronic use should be avoided as the long -term safety in older adults is not known)

Question 35

Enemas should only be used when?

Answer 35

to prevent fecal impaction in patients with several days of constipation

Question 36

what may be helpful in patients with dyssynergic defecation?

Answer 36

biofeedback therapy

Question 37

Timed toilet training that consists of

Answer 37

educationg patients to attempt a BM at least twice a day, usually 30 mins after meals, and to strain for no more than 5 minutes.

Question 38

How does fiber make you go?

Answer 38

Increases stool bulk, which causes colonic distention and promotes stool propulsion

Question 39

recommmended daily fiber intake

Answer 39

20- 25g per day. Increasing fiber intake may take several weeks to relive a patient’s constipation. Common problems with increasing fiber are bloating and flatulence.

Question 40

bulk forming laxatives include

Answer 40

psyllium seed (Metamucil)

methylcellulose (Citrucel)

wheat dextrimn (benefiber)

Question 41

how do bulk forming laxatives work

Answer 41

they absorb water and increase fecal mass. they are effective in increasing the frequency and softening the consistency of the stool with minimum adverse effects.

-can use alone or in combo with an increase in dietary fiber

Question 42

evaluation algorithm for chronic constipation

Answer 42

Question 43

treatment algorithm for slow transit constipation

Answer 43

Question 44

treatment algorithm for defecating disorders

Answer 44