ANSWERS VERIFIED 100% CORRECT
Causes of constipation - ANSWER 1) ↓ fiber/fluid or bad bowel habits
2) Systemic disease (e.g. thyroid, DM, metabolic disorders, neurologic
issues)
3) Medications (e.g. opioids, diuretics, CCBs, anticholinergics,
psychotropics, Ca or Fe supplements, NSAIDs)
4) Structural abnormalities
5) Slow colonic transit
6) Pelvic floor dyssynergia
7) IBS
(McPhee Table 15-3 and Shimp p 83-84)
Normal colonic transport time is _____________ hours; more
than ______________ hours is significantly abnormal. -
ANSWER Normal = 35 hours
Abnormal ≥ 72 hours
(McPhee p 592)
Gastrointestinal "alarm" symptoms which should prompt thorough
evaluation - ANSWER + Hematochezia (McPhee/Shimp) + Anemia
(McPhee/Shimp)
+ Weight loss ≥ 10 lbs (McPhee/Shimp)
+ Positive fecal occult blood test (McPhee/Shimp)
+ Family hx of colon cancer or IBD (Shimp)
+ New onset constipation in < 50 yr old pt without colon cancer screening
(Shimp)
+ Severe, persistent constipation not responsive to treatment
(Shimp)
+ Positive fecal immunochemical tests (McPhee)
, Increasing dietary fiber is NOT a good idea for patients with what
type of constipation? - ANSWER + Constipation r/t colonic r
inertia, defecatory disorders, opioid-induced constipation o
irritable bowel syndrome.
+ Fiber may make symptoms WORSE in these people
(McPhee p 593)
Lab testing for constipated patients with alarm symptoms - ANSWER +
Serum studies: CBC, electrolytes, calcium, glucose,
TSH (McPhee/Shimp)
+ Fecal occult test (Shimp)
+ Colonoscopy or flexible sigmoidoscopy
Recommended daily fiber intake - ANSWER 20 - 35 grams
Recommended daily fluid intake to prevent constipation -
ANSWER 32 ounces
Medications for treatment of constipation - ANSWER 1) Fiber laxatives
(e.g. bran, psyllium, methycellulose, guargum)
2) Surfactants (e.g docusate sodium, mineral oil)
3) Osmotic laxatives
--Saline laxatives (e.g. magnesium hydroxide)
--Hyperosmolar (e.g. lactulose, polyethylene glycol)
4) Stimulant laxatives (e.g. senna, bisacodyl) -- not for patients with
intestinal obstruction!
5) Enemas (e.g. warm water, mineral oil, sodium phosphate) 6)
Methylnaltrexone -- for opioid-induced constipation when pt has not
responded to other therapies.
McPhee Table 15-4, Shimp p 90)
Stool bolus causing constipation may be palpated WHERE on
the abdomen? - ANSWER LLQ.
What type of laxative should not be given to patient with chronic
,renal insufficiency? - ANSWER Avoid all laxatives containing
MAGNESIUM.
What kinds of medications should NOT be used for relief of constipation
in patients with a confirmed or suspected obstruction? - ANSWER Do
NOT give:
+ Bulk-forming agents
+ Stimulant laxatives
+ Intestinal secretagogues (e.g. lubiprostone)
+ Surfactants
+ Methylnaltrexone
Use osmotic laxatives with CAUTION.
(Shimp Table 12-4)
When should you refer patients with constipation? - ANSWER 1)
Pts with refractory constipation for anorectal testing
2) Pts with defecatory disorders who may benefit from
biofeedback
3) Pts with alarm symptoms OR who are over age 50 for
colonoscopy
4) Pts with severe colonic inertia may need surgical referral
(McPhee p 595)
Difference between acute and chronic diarrhea - ANSWER
Acute diarrhea < 2 weeks duration
Chronic diarrhea > 4 weeks duration
++ NOTE: Diarrhea persisting > 14 days is NOT caused by
bacterial pathogens (except for C.Difficile) and should be
evaluated as chronic diarrhea.
(McPhee p 596, 600)
Most common causes of acute diarrhea - ANSWER + Infectious
, agents
+ Bacterial toxins (either preformed or produced in gut)
+ Medications
(McPhee p 596)
Diarrhea-causing bacterial infection which increasingly affects
pregnant women? - ANSWER Listerosis
(McPhee p 596)
Viruses which cause diarrhea - ANSWER *Non-inflammatory*
Noroviruses
Astrovirus
Adenovirus
Rotavirus
Sapovirus
*Inflammatory*
Cytomegalovirus
(McPhee p 596)
Protozoa which cause diarrhea - ANSWER *Non-inflammatory*
Giardia
Cryptosporidium
Cyclospora
*Inflammatory*
Entamoeba histolytica
(McPhee p 596)
Bacteria which cause diarrhea - ANSWER *Non-inflammatory*
PREFORMED
S. aureus