CONSTIPATION
INTRODUCTION
- CLINICAL - DIFFERENTIALS
- WORKUP - TREATMENT
- FOLLOW-UP
Authored by Dave
Holson, MD, MPH, Clinical Assistant Professor, Department of Emergency
Medicine, Columbia University
Coauthored by Neill Oster,
MD, Assistant Site Director, Assistant Professor, Department of Emergency
Medicine, Mount Sinai School of Medicine, Elmhurst Hospital Center
Dave Holson, MD, MPH,
is a member of the following medical societies: Society for Academic Emergency
Medicine
Edited by William Chiang,
MD, Assistant Director, Assistant Professor of Clinical Surgery/Emergency
Medicine, Department of Emergency Medicine, Bellevue Hospital Center; Francisco
Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Eugene Hardin,
MD, Chair, Department of Emergency Medicine, Martin Luther King Jr/Charles
R Drew Medical Center; Medical Director, Hubert H Humphrey Comprehensive
Health Center; John Halamka, MD, Chief Information Officer, CareGroup Healthcare
System, Assistant Professor of Medicine, Department of Emergency Medicine,
Beth Israel Deaconess Medical Center; Assistant Professor of Medicine,
Harvard Medical School; and Barry Brenner, MD, PhD, Chairman, Department
of Emergency of Medicine, Professor, Departments of Emergency Medicine
and Internal Medicine, University of Arkansas for Medical Sciences
INTRODUCTION
Background: Constipation is a
symptom rather than a disease and is the most common digestive complaint
in the United States. A standard set of criteria has been suggested that
includes at least 2 of the following symptoms present for at least 3 months:
Hard stools
-
Straining at defecation
-
Sensation of incomplete evacuation at least
25% of the time
-
Two or fewer bowel movements per week
-
Pathophysiology: Constipation results from
a colonic or anorectal functional disorder.
Frequency:
In the US: More than 4 million people
have frequent constipation, a prevalence of about 2%. Constipation accounts
for an estimated 2.5 million physician visits per year.
Mortality/Morbidity: Most patients with
constipation can be treated medically, resulting in complete success or
improvement. However, a small percentage of patients are quite debilitated
as a result of constipation. Some patients with functional constipation
(ie, colonic inertia) require total abdominal colectomy with ileorectal
anastomosis.
Race: Constipation appears to affect people
of color 1.3 times more frequently than whites.
Sex: Male-to-female ratio is approximately
1:3.
Age: Constipation can occur in all ages,
from newborns to elderly persons. An age-related increase in the incidence
of constipation exists, with 30-40% of adults older than 65 years citing
constipation as a problem.
CLINICAL
History:
History provides the most useful information
about the etiology of constipation. Understanding the type and degree of
disability caused by the symptoms is important. Disability may include
the following:
-
Length of time attempting rectal evacuation
-
Number of bowel movements per week
-
Presence of chronic straining and/or hard
stools
-
The patient may be totally asymptomatic or
complain of the following:
-
Abdominal bloating
-
Pain on defecation
-
Rectal bleeding
-
Spurious diarrhea
-
Low back pain
The following also suggest that the
patient may have difficult rectal evacuation:
-
Feeling of incomplete evacuation
-
Digital extraction
-
Tenesmus
-
Enema retention
Physical:
General physical examination often is of
no benefit in determining etiology or deciding on treatment. The following
are exceptional findings:
A localized mass on abdominal examination
Local anorectal lesions, which can cause
or contribute to constipation (eg, anal fissures, fistulground: Constipation
is a symptom rather than a disease and is the most common digestive complaint
in the United States. A standard set of criteria has been suggested that
includes at least 2 of the following symptoms present for at least 3 months:
-
Hard stools
-
Straining at defecation
-
Sensation of incomplete evacuation at least
25% of the time
-
Two or fewer bowel movements per week (ed.
seriously, people have more than two per week?)
Pathophysiology: Constipation results
from a colonic or anorectal functional disorder.
Frequency: In the US: More than 4 million
people have frequent constipation, a prevalence of about 2%. Constipation
accounts for an estimated 2.5 million physician visits per year.
Mortality/Morbidity: Most patients with
constipation can be treated medically, resulting in complete success or
improvement. However, a small percentage of patients are quite debilitated
as a result of constipation. Some patients with functional constipation
(ie, colonic inertia) require total abdominal colecto hemorrhoids, strictures,
and tumors
-
Endocrinopathic and metabolic - Hypercalcemia,
hypokalemia, hypothyroidism, diabetes mellitus, and pregnancy
-
Neurologic - Stroke, Hirschsprung disease,
Parkinson disease, multiple sclerosis, spinal cord lesion, Chagas disease,
and familial dysautonomia
-
Connective-tissue disorders - Scleroderma,
amyloidosis, and mixed connective-tissue disease
-
Drugs
-
Antidepressants (cyclic antidepressants, monoamine
oxidase inhibitors [MAOIs]) Metals (iron, bismuth) Anticholinergics (benztropine,
trihexyphenidyl) Opioids (codeine, morphine) Antacids (aluminium, calcium
compounds) Calcium channel blockers (verapamil) Nonsteroidal anti-inflammatory
drugs (NSAIDs) such as ibuprofen or diclofenac Sympathomimetics (pseudoephedrine)
Cholestyramine and stimulant laxatives (long-term use)
-
Psychologic - Depression
-
Functional constipation
-
Simple constipation - Repressed defecatory
urge
-
Irritable bowel syndrome
-
Constipation with colonic dilatation - Idiopathic
megacolon or megarectum
-
Constipation without colonic dilatation -
Idiopathic slow transit constipation
-
Chronic intestinal obstruction
-
Rectal outlet obstruction - Anismus, solitary
rectal ulcer, intussusception
-
Weak pelvic floor - Descending perineum, rectocele
-
Ineffective straining
DIFFERENTIALS
Bowel Obstruction, Large
Other Problems to be Considered:
-
Diabetes mellitus Hyperparathyroidism Hypothyroidism
Lead poisoning Neuropathy Parkinson disease Scleroderma
WORKUP
Lab Studies:
-
Serum chemistry may exclude any metabolic
causes of constipation, such as hypokalemia and hypercalcemia.
-
Complete blood count (CBC) may reveal any
anemia that might be associated with rectal bleeding (gross or occult).
-
Thyroid function tests may be helpful with
patients suspected of having hypothyroidism.
Imaging Studies:
-
Plain film of the abdomen (upright and flat)
- This study underscores the amount of stool present in a patient’s colon.
Differentiation of fecal impaction, bowel obstruction, and fecalith is
possible.
-
Diagnosis of fecaliths is important because
of the dreaded complication of stercoral ulcers, which can lead to colonic
perforation.
-
Diabetic gastropathy, as well as fecal impaction,
may be seen in patients with diabetic neuropathy.
-
Residual barium (from barium enemas) can be
visualized.
-
Scleroderma and other connective-tissue diseases
may be complicated by motor disturbances that mimic colonic obstruction
on plain film.
-
Myxedema ileus is a consequence of hypothyroidism.
Other Tests:
-
An extensive workup of the constipated patient
is performed on an outpatient basis and usually occurs after approximately
3-6 months of failed medical management.
-
These tests are either anatomic (eg, Gastrografin
enema, proctosigmoidoscopy, colonoscopy) or physiologic (eg, colonic transit
study, defecography, manometry, electromyography).
Procedures:
-
Anoscopy: Routinely perform anoscopy on all
constipated patients to visualize anal fissures, ulcers, hemorrhoids, and
local anorectal malignancy.
-
Digital disimpaction: A well-lubricated gloved
finger might be required in patients with lower anorectal impactions.
-
Warm water enemas: These usually are unpopular
among the nursing staff and probably are not necessary within the ED.
TREATMENT
Emergency Department Care:
Most patients have chronic constipation,
which does not lend itself to a specific etiology at time of presentation.
-
A comprehensive history should readily identify
the most common causes of fecal impaction including (1) postoperative constipation,
(2) prolonged bed rest, (3) residual barium from barium enemas, or (4)
medication-related constipation (eg, opioids, anticholinergics).
-
In elderly bedridden patients, it is important
to exclude severe dehydration and electrolyte abnormalities.
-
Exclude any life-threatening complication
of constipation (eg, volvulus) and remember that the patient might present
with intestinal perforation after tap water enemas performed at home.
-
Specifically focus therapeutic interventions
on facilitating rectal evacuation rather than increasing bowel movement.
-
Consultations:
-
Consult a general surgeon if you suspect intestinal
obstruction or volvulus.
MEDICATION
The mainstay of treatment is a
high-fiber diet. Bulking agents usually are the next line of treatment.
Enemas can be used to assist in complete stool evacuation. Avoid irritant
or peristaltic stimulants (eg, senna). Chronic use has been reported to
induce damage to the myenteric plexus, which may eventually impair bowel
motility.
Drug Category: Bulk forming agents --
Used to increase fecal mass, which stimulates peristalsis. Drug Name Psyllium
(Metamucil, Fiberall) -- Promotes bowel evacuation by forming a viscous
liquid and promoting peristalsis. Adult Dose 1 tsp PO qd/tid with 8 oz
of liquid Pediatric Dose 6-12 years: Administer half of adult dose with
8 oz of liquid Contraindications Documented hypersensitivity; fecal impaction;
intestinal obstruction; colonic atony; undiagnosed abdominal pain Interactions
May decrease absorption and effects of salicylates, nitrofurantoin, tetracyclines,
and diuretics Pregnancy B - Usually safe but benefits must outweigh the
risks. Precautions Caution in intestinal adhesions, ulcers, or stenosis
Drug Name Methylcellulose (Citrucel)
-- Promotes bowel evacuation by forming a viscous liquid and promoting
peristalsis. Adult Dose 1 tbsp PO qd/tid with 8 oz of liquid Pediatric
Dose 6-12 years: Administer half of adult dose with 8 oz of liquid Contraindications
Documented hypersensitivity; fecal impaction; colonic atony; intestinal
obstruction; undiagnosed abdominal pain Interactions May decrease absorption
and effects of salicylates, nitrofurantoin, tetracyclines, and diuretics
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Caution in intestinal adhesions, ulcers, or stenosis
Drug Category: Emollients or softeners
-- Lower surface tension of stool and allow mixing of aqueous and fatty
substances, thereby softening stool. Drug Name Docusate (Colace, Surfak)
-- Allows the incorporation of water and fat into stool causing softening
of stool. Adult Dose 100 mg PO qd/bid Pediatric Dose <3 years: 10-40
mg/d PO qd or divided bid/qid >3-6 years: 20-60 mg/d PO qd or divided bid/qid
6-12 years: 40-150 mg/d PO qd or divided bid/qid >12 years: Administer
as in adults Contraindications Documented hypersensitivity; nausea; vomiting;
acute abdominal pain Interactions Decreases effects of warfarin and increases
effects of phenolphthalein Pregnancy A - Safe in pregnancy Precautions
Prolonged use of medication may result in electrolyte imbalance
Drug Category: Emollient stool softeners
in combination with stimulants -- Emollient stool softeners cause stool
to soften. Stimulants increase peristaltic activity in the GI. Drug Name
Docusate sodium and casanthranol combination (Peri-Colace, Diocto C, Silace-C)
-- Docusate sodium allows incorporation of water and fat into stool causing
stool to soften. Casanthranol is an anthraquinone stimulant hydrolyzed
by colonic bacteria into active compound. Usually produce action 8-12 h
after administration. Adult Dose 1-4 cap or tab PO qd Alternatively, 5-60
mL PO qd if syrup or emulsion given Pediatric Dose <6 years: Not recommended
>6 years: Administer as in adults Contraindications Documented hypersensitivity;
nausea, vomiting, GI bleeding, appendicitis, GI bleeding, congestive heart
failure, fecal impaction, appendicitis, nausea, vomiting, or acute abdominal
pain Interactions Decreases effects of warfarin and increases effects of
phenolphthalein Pregnancy C - Safety for use during pregnancy has not been
established. Precautions Excessive use may lead to electrolyte imbalance,
osteomalacia, steatorrhea, and cathartic colon
Drug Category: Osmotic laxatives
-- Act by retaining fluid in the bowel, osmosis, or altering the pattern
of water distribution in feces. Drug Name Magnesium hydroxide (Phillips'
Milk of Magnesia) -- Causes osmotic retention of fluid, which distends
colon and increases peristaltic activity. This in turn promotes emptying
of the bowel. Adult Dose 5-15 mL PO q6h prn Pediatric Dose 2.5-5 mL PO
prn up to qid Contraindications Documented hypersensitivity; colostomy;
ileostomy; renal failure; fecal impaction; appendicitis Interactions Decreases
effects of tetracyclines, digoxin, indomethacin, and iron salts Pregnancy
A - Safe in pregnancy Precautions Caution in severe renal impairment
Drug Name Sodium phosphate (Fleet enema)
-- Through osmotic effects, these agents draw water from the intestine
into the lumen of the gut, producing distention and promoting bowel emptying.
Adult Dose 1 adult (4.5 fl oz) enema PR Pediatric Dose 1 pediatric (2.25
fl oz) enema PR Contraindications Documented hypersensitivity; hypernatremia;
hyperphosphatemia; renal failure; hypocalcemia; fecal impaction Interactions
Do not administer aluminum, magnesium antacids, or sucralfate Pregnancy
A - Safe in pregnancy Precautions Hypocalcemia, hyperphosphatemia, hypernatremia,
and acidosis in patients with renal difficulties; caution in congestive
heart failure and cirrhosis
Drug Name Polyethylene glycol solution
(Miralax) -- For treatment of occasional constipation. In theory, less
risk of dehydration or electrolyte imbalance with isotonic polyethylene
glycol compared with hypertonic sugar solutions. Laxative effect generated
because polyethylene glycol is not absorbed and continues to hold water
by osmotic action through small bowel and colon, resulting in mechanical
cleansing. Supplied with measuring cap marked to contain 17 g of laxative
powder when filled to indicated line. May require 2-4 d (48-96 h) to produce
bowel movement. Adult Dose 17 g/d in 8 oz of water Pediatric Dose Not established
Contraindications Documented hypersensitivity; colitis, megacolon, bowel
perforation, gastric retention, or GI obstruction Interactions Reduces
effectiveness and absorption of oral medications Pregnancy C - Safety for
use during pregnancy has not been established. Precautions Caution in ulcerative
colitis and hot loop polypectomy; not for use >2 wk
Drug Name Lactulose (Cephulac, Cholac,
Constilac) -- Produces an osmotic effect in the colon, resulting in
distention and promoting peristalsis. Action may take up to 48 h. Adult
Dose 15-30 mL PO qd/bid Pediatric Dose <1 year: 2.5 mL PO bid 1-5 years:
5 mL PO bid 6-12 years: 10 mL PO bid Contraindications Documented hypersensitivity;
galactosemia; intestinal obstruction Interactions Decreases effects of
neomycin, laxatives, and antacids Pregnancy B - Usually safe but benefits
must outweigh the risks. Precautions Adverse effects include flatulence,
cramps, and abdominal discomfort; caution in diabetes mellitus; monitor
for electrolyte imbalance
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FOLLOW-UP
Further Inpatient Care:
Patients with the following warrant admission
and surgical evaluation:
-
Obstructive symptoms
-
Nonrectal impactions
-
Fever and dehydration
-
Further Outpatient Care:
Further outpatient care should include
contact with the primary care physician to ensure follow-up.
-
Referral to a gastroenterologist is warranted
for patients with the following:
-
Constipation of recent onset
-
Chronic constipation associated with weight
loss, anemia, or change in stool consistency
-
Refractory constipation
-
Constipation requiring chronic laxative use
In/Out Patient Meds:
Bulk-forming agent: Psyllium (eg, Metamucil)
increases frequency and softens stool consistency.
Emollient: Docusate sodium (eg, Colace) improves
hard bowel movements.
Lukewarm tap water enema: This treatment facilitates
rapid relief of symptoms and may help regulate further bowel movements.
Deterrence/Prevention:
Adequate fluid intake (ie, eight 8-oz glasses
of water per day)
Regular exercise
High-fiber diet
Avoidance or decreased use of constipating
medications
Regular bowel habits with attempted bowel
movements at the same time daily may help symptoms, especially after meals
when the gastrocolic reflex is strongest.
Complications:
-
Anal fissures
-
Fecal impaction
-
Bowel obstruction
-
Fecal incontinence
-
Stercoral ulceration
-
Megacolon
-
Volvulus
-
Rectal prolapse
-
Urinary retention
-
Syncope
Prognosis:
-
Most active patients do well with medical
management.
-
Constipation is an ongoing problem for patients
who are bedridden or otherwise debilitated.
-
Colectomy usually is reserved for patients
with slow transit constipation who fail to respond to 6 months of medical
management with good patient compliance.
Patient Education:
-
Listening to patients' concepts of normal
bowel activity is important.
-
Instituting a behavior modification program
allows patients to become more aware of and responsive to normal urges
to defecate.
-
Emphasize the importance of a high-fiber diet.
-
Emphasize adequate fluid intake.
-
Emphasize regular exercise.
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