This document discusses constipation, defining it as a broad term with variable meaning. It defines functional constipation according to the Rome III criteria and discusses pathophysiology. Constipation can be classified into 3 subtypes: IBS-C, colonic transit disorder, and obstructed defecation syndrome. Diagnosis involves a history, physical exam, and various tests depending on whether investigating for secondary causes or primary/idiopathic constipation. Management depends on the subtype and may involve lifestyle changes, medications, surgery, biofeedback, or sacral nerve stimulation.
2. • Constipation is a broad term used by both patients and practitioners,
with variable meaning .
2
3. The Rome III definition of functional constipation requires:
• 12 weeks of symptoms in the past 6 months, including at least 2 of the
following symptoms:
o straining at defecation on at least 25% of defecations,
o lumpy or hard stools in at least 25% of defecations,
o sensation of incomplete evacuation for at least 25% of defecations,
o sensation of anorectal obstruction/blockage for at least 25% of
defecations,
o manual maneuvers to facilitate at least 25% of defecations (eg, digital
evacuation, support of the pelvic floor), and
oless than 3 defecations per week
3
5. Pathophysiology and Etiology
• Multiple conditions and medications can result in functional constipation
• Constipation can be classified into 3 broad subtypes:
constipation-predominant irritable bowel syndrome (IBSC),
colonic transit disorder, and
obstructed defecation syndrome (ODS).
5
6. • IBS-C is a functional gastrointestinal disorder characterized by
recurring symptoms of abdominal pain, bloating, and altered bowel
habits.
• Irritable bowel syndrome (IBS) is suspected by:
recurrent abdominal
pain or discomfort ,
at least 3 days per
month in the past 3
months
associated with 2 or more of the following:
• improvement with defecation,
• onset associated with a change in
frequency of stool, and
• onset associated with a change in form
(appearance) of stool.
IBS symptoms are not treated surgically.
6
7. • Colonic transit disorder is a gastrointestinal dysmotility syndrome.
Symptoms suggestive of slow transits include:
• long intervals between bowel movements,
• bloating,
• abdominal distention,
• megacolon, and
• secondary small bowel obstruction due to constipation.
7
8. ODS is associated with a range of symptoms including:
• incomplete and/or painful evacuation,
• excessive straining,
• sensation of incomplete evacuation,
• and the need to insert a finger into the vagina or anus in order to
evacuate bowel contents (ie, “splinting”).
ODS accounts for 50% of constipation cases and is most commonly
seen in women older than age 65years.
It has a 60% association with both depression and anxiety.
8
11. (a) pelvic floor muscles at rest with preservation of the normal anorectal angle;
(b) contraction of abdominal muscles and relaxation of puborectalis and external sphincter
muscles leading to straightening of the anorectal angle;
(c) relaxation of internal sphincter and evacuation of stool with rectal contraction
11
12. (d) puborectalis dyssynergia: the puborectalis sling has paradoxically shortened during straining,
leading to exaggeration of the anorectal angle and obstruction of fecal progression;
(e) rectocele: feces is pushed during straining into the vagina, which then retains feces at defecation, leading
to incomplete evacuation; and
(f) rectal intussusseption: the rectum has internally prolapsed, leading to obstructed defecation during
straining.
12
13. Diagnosis and Evaluation
• The above subtypes of constipation are not mutually exclusive and often coexist .
In absence of ALARM SYMPTOMS, such as :
• new onset of symptoms at 50 years or older,
• unintentional weight loss,
• nocturnal diarrhea,
• anemia,
• bloody stools,
• family history of colon cancer,
• celiac disease, or
• inflammatory bowel disease,
patients can be initiated on an empiric trial of fiber therapy, especially if their
symptoms appear consistent with IBS-C .
13
14. • However, if routine medical therapy fails, further diagnostic testing should
be considered to further determine the etiology of constipation.
• Initially, the evaluation should always be guided by a careful history and a
complete perianal and anoscopic examination.
• Laboratory studies for thyroid hormone and calcium levels
can exclude metabolic etiologies of constipation.
• Endoscopy can evaluate for obstructing colonic lesions, diverticular
strictures, or inflammatory bowel disease.
• In absence of obvious obstruction, subsequent workup of constipation
should attempt to exclude functional constipation. To accomplish this,
patients should undergo anorectal physiology and colonic motility testing.
14
16. History
• Probably first and foremost is the determination of whether
constipation represents a new complaint ?
16
17. • We specifically ask about the following, with and without laxatives (if
relevant):
• Frequency of spontaneous or assisted bowel opening
• Painful defecation
• Stool consistency
• Digitation (vaginal or anal)
• Straining
• Abdominal pain
• Incomplete evacuation
• Bloating
• Unsuccessful evacuation with or without toilet revisiting
• The remaining history should document prescribed and self-administered
laxatives (and the therapeutic benefit thereof) and gain an impression of
the quality of diet with respect to fiber and fluid intake.
17
18. • patients with chronic idiopathic constipation are usually female (90%
or more), and often have symptoms from early childhood or puberty
(at least 50%) or problems that start after pelvic surgery, for example,
hysterectomy or childbirth .
18
19. Physical Examination
• During the physical examination, it is important to make a quick
assessment of the patient’s nutritional status.
• In general, patients with idiopathic constipation should not appear
malnourished;
• the appearance of malnutrition should prompt a more extensive
search for a secondary cause, including occult carcinoma, more
widespread dysmotility syndromes such as chronic intestinal pseudo-
obstruction, and eating disorders.
19
20. • An abdominal examination should be conducted to
look for scars, any significant abdominal distention, tenderness, or
masses.
• Bloating is a common and expected finding with idiopathic
constipation, but significant distention, tenderness, or masses should
prompt a full investigation.
20
22. investigative studies
• In general, diagnostic studies can be divided into :
1. those conducted to rule out an underlying cause of secondary
constipation (e.g., partially obstructing colon cancer, metabolic or
endocrine cause) and
2. those used to diagnose specific anorectal or colonic physiologic
abnormalities associated with chronic idiopathic constipation.
22
23. Investigations for Secondary Causes of
Chronic Constipation
• serum calcium concentrations,
• thyroid function tests,
• hemoglobin concentrations,
• glucose levels,
• serum electrolyte levels,
• creatinine concentrations are usually performed.
23
24. Investigations for Secondary Causes of
Chronic Constipation
• The approach taken to structural investigation of the colon when
patients have no suspected intraluminal pathology varies
internationally and on the basis of available resources.
• In the United States, for patients older than 50 years, the baseline risk
of colorectal cancer is sufficiently high that screening colonoscopy is
recommended even in the absence of alarming symptoms.
24
25. Investigations for Secondary Causes of
Chronic Constipation
• Barium enema can still be a useful investigation in this instance
because it yields more information on colonic diameter (for rarer
cases of megacolon) and the distribution and severity of diverticular
disease, which may coexist and be responsible in part for
symptomatology.
25
27. • ANORECTAL PHYSIOLOGY TESTING
Anal manometry is one of the main testing procedures performed
with the goal of delineating the etiology of constipation
• Anal resting and squeeze pressures are calculated at each centimeter
starting at 6 cm from the anal verge. The high-pressure zone is
identified, and mean resting, maximum resting, and maximum
squeeze pressures are calculated.
27
28. • In addition, the test includes a quantification of rectoanal inhibitory
reflex (RAIR). The RAIR describes the relaxation of the internal anal
sphincter with distension of the rectum.
• Notable causes for absence of the reflex include Hirschsprung disease,
circumferential myotomy, and overly aggressive lateral sphincterotomy .
• Other relevant findings on anorectal manometry in a patient with
constipation may be the presence of elevated resting and squeeze
pressures, which may suggest ODS .
28
29. • BALLOON EXPULSION TESTING
• Balloon expulsion testing is an easy, inexpensive way to evaluate
evacuation.
• A balloon is inserted in the rectum and inflated to 60 mL. Patient are
asked to expel the balloon on a commode, with the expectation that
a normal subject should be able to do so within 1 to 5 minutes.
• Patients unable to expel the balloon are suspected to have outlet
obstruction.
• The test does not differentiate between the causes of outlet
obstruction(dyssynergia vs anatomic)
29
30. • ELECTROMYOGRAPHY
• Electromyography (EMG) aids in the diagnosis of pelvic floor
dyssynergia due to a nonrelaxing puborectalis.
• A small EMG sponge containing 2 electrodes is gently positioned into
the rectum and then pulled back until the recording electrodes lodges
in the anal sphincter. EMG tracings are then obtained at rest, squeeze,
and push.
• The presence of reproducible contractions when the patient
attempts to push the sponge out is defined as abnormal.
30
31. • DEFECOGRAPHY
• Many specialist centers use defecography (also known as evacuation
proctography) to evaluate evacuation.
• Barium paste is formulated so as to simulate a fecal bolus and is placed in the rectum.
The patient is asked to defecate on a radiolucent commode, and the event is recorded
with fluoroscopy.
• During normal defecation, the puborectalis and the anal sphincter muscles
relax, and the rectum assumes a more vertical position with respect to the anal canal,
facilitating evacuation of stool.
• In a patient with puborectalis dyssynergia, defecography typically demonstrates failure
to open the anorectal angle and persistence of the puborectalis impression during
defecation, as well as failure to empty completely.
• Other important findings that may also be noted include rectocele, internal
intussusception, and rectal prolapse.
31
32. • COLONIC TRANSIT TESTING
A number of options are available to assess colonic transit time
• The most widely available technique involves ingestion of radiopaque
markers and serial abdominal radiography
• Patients must prepare for the test by refraining from all enemas,
laxatives, and nonessential medications 2 days before the test.
• Capsules containing 24 radiopaque markers are ingested. An
abdominal radiograph is obtained at 5 and 7 days, and colonic transit
is deemed abnormal if >30% of markers are retained.
32
33. • The pattern of accumulation is also diagnostics.
• Left-sided or rectal accumulation suggests ODS,
• whereas right and transverse colon distribution suggests colonic
inertia
33
35. Management
Chronic Idiopathic Constipation
• The hallmark of medical management is increasing fiber in a patient’s
diet.
• Fiber can be either soluble (eg, nuts, beans, fruit, lentils, vegetables,
barley) or insoluble (eg, whole wheat, whole grain, vegetables, wheat
bran).
• Osmotic laxatives are first-line therapy and include polyethylene
glycol (PEG)-based products as well as milk of magnesia.
• Stimulant laxatives, such as bisacodyl (Dulcolax) and senna (Senocot),
should be used with caution due to concern about addiction.
35
36. Slow-Transit Constipation
• In this group, the mainstay of therapy is the use of osmotic
and stimulant laxatives (alone or in combination) to effect
changes in transit .
36
37. • A theoretical problem with all classic laxative therapies is their
bioavailability in the colon. All require transport to the colon for site
of action, and some require metabolism via the enteral flora to
produce active products, for example, hydrolysis of stimulant
laxatives.
• Furthermore, laxatives are often poorly tolerated because of pain
(mainly stimulant) or unpredictable diarrhea with or without
incontinence (mainly osmotic).
• Given the burden of disease, much investment has been made to find
newer classes of drug to treat chronic constipation. To date, two
classes of drug are being developed:
1. colonic prokinetics, based on activity at serotonin receptor subtype
4 (5-HT4 agonists), and
2. intestinal secretagogues.
37
38. • The main development in the 5-HT4 agonist class is prucalopride.
This drug has much greater selectivity to the 5-HT4 receptor than the
now withdrawn 5-HT4 agonists such as tegaserod and cisapride. In
particular, it has no proven effect on QTc interval
• prucalopride leads to increases in:
1. propagated colonic contractile activity,
2. leading to coordinated mass movements and
3. spontaneous defecation.
In particular, it has a significant advantage over laxatives in terms of
reducing rather than increasing abdominal pain and bloating.
38
39. • Two drugs :
1. lubiprostone (a chloride channel activator) and
2. linaclotide (a guanylate cyclase C receptor activator),
accelerate colonic transit in humans by mediating luminal secretion.
39
40. SURGERY
• Surgery for constipation should be considered only after :
• medical therapy has failed and
• symptoms severely compromise activities of daily living.
• Interventions are divided into procedures for:
slow transit constipation and
those for obstructed defecation.
40
41. Procedures for Treating Slow Transit Constipation
• Subtotal Colectomy
For patients with documented severe slow transit constipation
without ODS, a subtotal colectomy with ileorectal anastomosis should
be strongly considered.
Proper patient selection is crucial to the success of surgery.
41
42. • Nevertheless, most would agree that colectomy continues to have a
limited role as a treatment option for highly selected patients with
proven STC (probably < 5% chronic constipation) who have failed all
nonsurgical interventions and in whom symptoms are sufficiently
severe to contemplate major surgery.
42
43. • Subtotal colectomy with ileorectal anastomosis has the best results,
leading to a median stool frequency of three (range one to five) per
day.
• Unfortunately, surgery may not satisfactorily alleviate other
symptoms (e.g., abdominal discomfort or bloating), and patients
should be made aware of this possibility before operation .
43
44. • Sacral Nerve Stimulation
• First developed for urinary and fecal incontinence, the use of sacral
nerve stimulation (SNS) to treat both slow transit and pelvic floor
constipation has increased, especially in Europe.
• Mechanistically, SNS increases pancolonic anterograde propogated
sequences in patients with STC .
44
45. • Antegrade Colonic Enema
Antegrade colonic enema involves creation of either an appendiceal
conduit or an indwelling cecostomy catheter followed by regularly
scheduled instillation of either water or PEG solution.
This procedure is most frequently used in the pediatric population, and
adult data are limited but encouraging .
45
46. • Stoma
For patients with slow transit constipation accompanied by bloating
and abdominal pain, an ileostomy can be both destination therapy
and a diagnostic tool to determine if symptoms are attributable to the
small or large intestine.
46
47. Evacuation Disorder
• Patients with large rectoceles in whom clinical (the patient can
successfully effect evacuation by digital pressure in the vagina) and
radiologic findings concur should have these repaired by one of the
numerous transvaginal, transperineal, or transanal approaches.
47
48. • For patients with ODS and/or dyssynergy, biofeedback therapy
should be first-line therapy .
• Biofeedback teaches patients to relax the anus and puborectalis
during defecation.
• It appears to be very effective in treating ODS, with 63% of patients
with constipation having improvement after ≥ 5 training sessions,
48
49. • Regardless of whether or not an anatomic cause of ODS is identified
on defecography, surgical intervention is only considered in patients
who failed medical management and ≥ 6 biofeedback training
sessions.
49
50. • Botulinum Toxin Type A (Botox)
To augment biofeedback teaching and retraining, botulinum toxin
type A (BTX-A;Botox) injections have been proposed as a method to
induce chemical denervation of the puborectalis.
• Results are mixed. Although 75% achieved manometric relaxing, only
29.2% had symptomatic improvement on a straining index .
50
51. • Stapled Transanal Rectal Resection (STARR)
STARR was designed to treat the anatomic abnormality of internal
intussusception and/or rectocele . This eliminates the obstruction
caused by the intussuscepting rectum and/or rectocele into the anus
and the ODS attributable to these.
51
52. • Ventral Rectopexy
Ventral rectopexy involves suspension of the anterior rectum to the
sacral promontory with mesh.
52
53. • Stoma
For patients with isolated severe outlet obstruction, end colostomy
can be considered. As stated earlier, when a slow transit component
exists as well, an ileostomy is more appropriate.
53
54. Conclusion
• Aggressive medical management is always the first, second, and third
step.
• Many patients with ODS symptoms will also benefit from
biofeedback.
• Surgery is an option of last resort with borderline efficacy.
• Patient collaboration with treatment is essential in ensuring long-
lasting success.
54