2. Anorectal physiology
• The rectum function as a capacitance organ
with a reservoir of 650 to 1200 ml compared to
an average daily stool output of 250 to 750 ml
• The anal sphincter mechanism allows
defecation and maintains continence.
3. • The internal sphincter (involuntary) accounts for
80% of resting pressure, whereas the external
sphincter (voluntary) accounts for 20% of
resting pressure and 100% of squeeze
pressure. The external anal sphincter contracts
in response to sensed rectal contents and
relaxes during defecation.
4. Defecation
• Defecation has four components:
1. Mass movement of feces into the rectal vault.
2. Rectal-anal inhibitory reflex, by which distal rectal
distention causes involuntary relaxation of the
internal sphincter and external sphincter contracts
(this process in k/a sampling and allows for
determination of contents as gas, liquid, or solid.
5. 3. Voluntary relaxation of the external
sphincter mechanism and puborectalis
muscle
4. Increased intraabdominal pressure.
6. Normal Continence
• To relies stool on coordinated interplay several
factors are necessary:
– Stool consistency
– Rectal capacity
– Compliance
– Intact neural pathways
– Normal anal sphincter and pelvic floor function
– Normal anorectal sensation.
7. Fecal incontinence
• Anal incontinence= Fecal incontinence +flatus
incontinence.
• Fecal incontinence: Recurrent uncontrolled
passage of fecal material for at least 1 month.
• Partial incontinence: inability to control anal
sphincter resulting passage of flatus and fecal
soiling.
12. Sphincter injury
In adult female most common cause is obstetric
trauma: Vaginal delivery:
• up to 10% primipara have a clinically
recognised sphincter disruption.
• Vaginal Sonographically 30%
• Instrumental
• Large birth weight
• Prolonged second stage
13. Active (urge incontinence)
• Loss of stool despite best effort.
–Intact sensory
–Derangement in external anal sphincter
–Rectal pathology: noncompliant rectum,
Inflammatory bowel disease, Radiation
proctitis, carcinoma
14. Passive incontinence
–Loss of stool without patients awareness
–Internal anal sphincter pathology
–Neurological etiology
–Fistula in ano
–Post surgical scarring
15. Cleveland clinical score of fecal
incontenence
• Type never rarely sometimes usually always
• Solid 0 1 2 3 4
• Liquid 0 1 2 3 4
• Gas 0 1 2 3 4
• Pad use 0 1 2 3 4
• QOL 0 1 2 3 4
• Score of 0 indicates perfect continence, 20 is
complete incontinence
16. Mechanism
• Fecal loading or impaction: overflow incontinence
– Easily diagnosed on DRE. When empty the
mechanisms are:
• Diarrhea or loose stool
• Rectal volume/compliance reduction
• Sphincter complex: anatomical or functional
disruption.
28. Anterior Sphincter Repair
• EAS defect
• Overlapping vs direct
apposition
• 80% improved
• Function deteriorates
with time
29. Artificial Bowel Sphincter
• Currently used silicone made, pressure
regulated
• Inflatable cuff placed around the lower rectum
or upper anal canal
• A pump placed in the labia majora or scrotum
• Pressurisation fluid is an isotonic solution.
30. • Walls are semipermeable and radioopaque.
• Three models
• Severe FI.
• To initiate defecation, squeezing the pump
empties the cuff by transferring fluid into the
ballon, permitting passage of stool
31. • Cuff then refills automatically from pressure
built up in the balloon.
• Careful patient selection and sound operative
technique for success
32.
33. Artificial Bowel Sphincter
• Not recommended
for routine use
• Only in cases of
severe sphincter
injury, malformation
or loss.
34. Injection therapy
• Bulking effect of injected materials with
subsequent fibrosis/collagen deposition helps to
enhance continence.
• Injected into either submucosa or the
intersphincteric plane
• Routine use of ultrasound guidance improve
outcome.
36. • Relative simplicity of the procedure, safe, only
minor complications
• Effects of bulking agents appear to be short
lived and of limited efficacy
• Recommended for use in only selected cases
of mild passive faecal incontinence related to
IAS dysfunction and soiling
37. Stoma
• Antegrade continence enema:
–Appendicostomy, by invaginating the tip of
the appendix into the caecum to create a one
way valve.
–Base of the appendix is tghen brought out to
the abdominal wall
–Antegrade enema
38. • Caecal or ileal tube
–Can also be performed percutaneoulsy
guided by a colonoscope and a specially
designed catheter.
–Minimally invasive, safe and useful for both
paediatric patients and adults.
39. • Significant reduction in incontinence
scores compared to preoperative values.
• Morbidity: wound infection and leakage
from the mini stoma.
40. End stoma
• Severe end stage FI, in which
– All other available treatments have failed
– Are inappropriate because of comorbidities, or
– When preferred by the patient.
• Significant psychosocial issues and stoma related
complication Vs it resumes normal activities and
improves quality of life.
41. • In FI 83% reported a significant improvement in
life style and 84% would choose to have the
stoma again.
• End sigmoid colostomy without proctectomy
(Hartman’s procedure) is usualy procedure of
choice.
• Diversion colitis of the rectal stump and mucus
leakage infrequently necessitating a secondary
proctectomy.
42. SNS
• First described in urological disorders
• Function
– Anal sphincters
– Pelvic floor musculature
– Effect on colonic motility
– Local spinal reflex arcs
– Reduce the rectal sensory threshold
– Increase rectal blood flow
43. • Screening phase of peripheral nerve evaluation
–Under L/A OR G/A
–Prone position
–S3 foramen is preferntially cannulated under
flouroscopic guidance with an electrode
44. • Bellows response of the pelvic floor and plantar
flexion of the ipsilateral great toe.
• Sometimes repeated on the contralateral side
to select the best response with screeening of
S2 and S4 as well.
45. –Electrode is secured in place and connected
to a portable external stimulator.
–3 week trial of stimulation while filling out a
bowel habit diary.
• Second therapeutic phase of permanent
neurostimulatior implantation.
48. Constipation
• Constipation is a symptom not a disease.
• According to the Rome III criteria for constipation,
a patient must have experienced at least 2 of the
following symptoms over the preceding 3 months.
Fewer than 3 bowel movements per week
Straining
49. Lumpy or hard stools
Sensation of anorectal obstruction
Sensation of incomplete defecation
Manual maneuvering required to defecate
50. Pathophysiology
• Constipation may originate primarily from within
the colon and rectum or may originate
externally:
Colon obstruction (neoplasm, volvulus,
stricture)
Slow colonic motility, particularly in patients with
a history of chronic laxative abuse
51. Outlet obstruction as Anatomic outlet
obstruction:- intussusception, rectal prolapse,
and rectocele; functional outlet obstruction:-
puborectalis or external sphincter spasm when
bearing down, Hirschsprung disease, and
damage to the pudendal nerve, typically related
to chronic straining or vaginal delivery
52. Etiology
• The etiology of constipation is usually
multifactorial, but it can be broadly divided into
2 main groups:
1. Primary constipation
2. Secondary constipation.
53. Primary
• Primary (idiopathic, functional) constipation can
generally be subdivided into the following 3
types:
Normal-transit constipation (NTC)
Slow-transit constipation (STC)
Pelvic floor dysfunction (ie, pelvic floor
dyssynergia)
54. Normal-transit constipation
(NTC)
• most common
• Stool passes at a normal rate but difficult to
evacuate their bowels.
• Patients in this category sometimes meet the
criteria for IBS with constipation (IBS-C).
55. • The primary difference between chronic
constipation and IBS-C is the prominence of
abdominal pain or discomfort in IBS. Patients
with NTC usually have a normal physical
examination.
56. Slow-transit constipation (STC)
• Infrequent bowel movements, decreased
urgency, or straining to defecate. More
commonly in females. Patients have impaired
phasic colonic motor activity, mild abdominal
distention or palpable stool in the sigmoid
colon.
57. • Pelvic floor dysfunction or anal sphincter
defect:- Patients often report prolonged or
excessive straining, a feeling of incomplete
evacuation, or the use of perineal or vaginal
pressure during defecation to allow the passage
of stool, or they may report digital evacuation of
stool.
58.
59. Secondary constipation
Dietary issues that may cause constipation include
inadequate water or fiber intake; overuse of coffee,
tea, or alcohol; a recent change in bowel habit
paralleled by changes in the diet; and ignoring the
urge to defecate. Reduced levels of exercise may
play a role as well.
60. • Structural causes of secondary constipation
include anal fissures, thrombosed hemorrhoids,
colonic strictures, obstructing tumors, volvulus,
and idiopathic megarectum
61. Systemic diseases that may cause
constipation
• Endocrinologic and metabolic disorders -
Hypercalcemia, hyperparathyroidism,
hypokalemia, hypothyroidism, pregnancy, and
diabetes mellitus (constipation is the most
common gastrointestinal problem affecting the
diabetic population)
63. Medications that may contribute to
constipation
Antidepressants (eg, TCA and MAO inhibitors)
Metals (eg, iron and bismuth)
Anticholinergics (eg, benztropine and
trihexyphenidyl)
Opioids (eg, codeine and morphine)
65. • Psychological issues (eg, depression, anxiety,
somatization, and eating disorders) may also
contribute to the development of constipation.
66. Signs and symptoms
• A constipated patient may be otherwise totally
asymptomatic or may complain of 1 or more of
the following:
Abdominal bloating
Pain on defecation
Rectal bleeding
67. Spurious diarrhea
Low back pain
Feeling of incomplete evacuation
Digital extraction
Tenesmus
Enema retention
68. • The following signs and symptoms, if present,
are grounds for particular concern:
Rectal bleeding
Abdominal pain (s/o possible irritable bowel
syndrome [IBS] with constipation [IBS-C])
Inability to pass flatus
Vomiting
69. Diagnosis
In patients with acute abdominal pain, fever,
leukocytosis, or other symptoms suggesting
possible systemic or intra-abdominal
processes, imaging studies are used to rule out
sources of sepsis or intra-abdominal problems
70. • DRE
• X ray abdomen supine/erect
• Lower gastrointestinal (GI) endoscopy,
• colonic transit study,
• defecography,
• anorectal manometry,
• surface anal electromyography (EMG)
• balloon expulsion may be used in the evaluation of
constipation
76. Management
• Diet modification- increasing intake of fiber and
fluid
• Initial treatment for constipation include manual
disimpaction and transrectal enemas.
77.
78. Medications to treat constipation
Bulk-forming agents (fibers; eg, psyllium): best and
least expensive medication for long-term treatment
Emollient stool softeners (eg, docusate): Best used
for short-term prophylaxis (eg, postoperative)
81. • Laxatives are used
1) To treat constipation
2) To avoid undue straining at defecation
3) Before or after any anorectal surgery
4) In bedridden patients
Laxatives have mild activity and are usually stool
softeners.
82. • Purgatives are used for complete colonic
cleansing prior to GI endoscopic procedures,
pre-post MI bed ridden patients , to prepare
bowel before surgery or abdominal X-ray.
• Purgative either provide semisolid stool or lead
to watery evacuation
• In low doses these can be used as laxative also
83. Bulk forming
• AKA roughage and these are luminally active,
hydrophilic indigestible vegetable fibres
• Acts on small and large intestine
• Stimulates peristalsis and defecation reflexes
by increasing faecal bulk
84. • Adequate water must be taken with all Bulk
forming agents b’coz they absorb water
• Effect appears within 1-3 days
• Eg:- Metamucil, Citrucel, Fibrocon
• S/E Bloating and flatus causing abdominal
discomfort
85. Stool softener/Emollient agents
• They enable additional water and fats to be
incorporated in the stool, making it easier for
them to move through the GI tract (small and
large intestine).
• Also known as surfactant laxatives (anionic
surfactants)
• 100-400 mg oral per day in divided doses
86. • They prevent constipation rather than treating long
term constipation.
• Indicated when straining at defecation is avoided
• Latency period 1-3 day
• Bitter in taste can cause nausea
• Cramps and abdominal pain may occur
• Eg:- Docusate, Gibseze
87. Stimulant purgative
• Acts on the intestinal (colon) mucosa or nerve
plexus, altering water and electrolyte secretion.
They also stimulates peristaltic action and can be
dangerous under certain circumstances.
• They are most powerful among laxatives and
should be used with care. Prolonged use can
create drug dependence by damaging the colon’s
haustral folds making user less able to move feces
through the colon on their own.
88. • Onset of action 6-10 hours
• Eg:- senna, bisacodyl
• Larger dose of stimulant purgative can lead to
purgation resulting in fluid and electrolyte
imbalance, hypokalemia.
• Can reflexly stimulate gravid uterus- C/I in
Pregnancy
• Also C/I- Subacute or Chronic intestinal
obstruction
89. Bisacodyl: (DULCOLAX 5 mg)
• Partly absorbed and re-excreted in bile.
• Activated in intestine by deacetylation.
• Primary site of action is colon- Irritate mucosa,
produce inflammation & increase secretion
• Effect appears within 6-8 hrs.
90. Anthraquinones
• Senna : Leaves and pods of Cassia species.
• Cascara sargada: bark of buck thorn tree
• Degraded by colonic bacteria to liberate anthrol
form which either acts locally or absorbed into
circulation and excreted in bile to act on small
intestine
91. • Takes 6-8 hrs to produce action
• Active principle of these drugs act on myenteric
plexus to increase peristalsis and decrease
segmentation
92. Osmotic purgatives
• They causes the intestine (colon) to hold more
water within and creates osmotic effect that
stimulates a bowel movement.
• Onset of action 12-72 hours(oral), 0.25-1
hour(rectal).
• Eg:- glycerin supp, sorbitol, lactulose, and PEG
93. Saline Laxatives
• Magnesium salts release Cholecystokinin which
further helps in increasing intestinal secretions
and peristalsis
• Milk of Magnesia is most commonly used ,
other salts have an unpleasant taste
94. • Usually preferred for bowel preparation before
surgery, colonoscopy, in food/drug poisoning
and as after purge in treatment of tapeworm
infestation
• Should not be used for prolonged period in pt
with renal insufficiency due to risk of hyper-
magnesemia.
95. Lubricant laxative
• They coat the stool with slippery and retard
colonic absorption of water so that the stool
slides through the colon more easily and they
increases the weight of stool and decrease
intestinal transit time.
• Onset of action:- 6-8 hours
• Eg:- mineral oil
96. Lactulose(DUPHALAC
10gm/15ml syp)
• Semisynthetic disaccharide of fructose and
lactose, neither digested nor absorbed in small
intestine-retains water
• Broken down in the colon by bacteria to
osmotically more active product
• Produces soft, formed stool in 1-3 days.
97. • Flatulence and flatus is common , cramps occur
in few, some pt may feel nauseated due to
peculiar sweet taste
• Also used for tt of hepatic encephalopathy in
dose of 20gm TDS orally
• Lactulose is degraded to lactic acid and
converts NH3 to ionised NH4+ salts which is
then excreted.
98. Miscellaneous
Rapidly acting lubricants (eg, mineral oil): Used for
acute or subacute management of constipation
Prokinetics (eg, tegaserod): Proposed for use with
severe constipation-predominant symptoms
Stimulant laxatives (eg, senna): Over-the-counter
agents commonly but inappropriately used for
long-term treatment of constipation
99. Prucalopride (not approved in the United
States), a prokinetic selective 5-
hydroxytryptamine-4 (5-HT4) receptor
antagonist that stimulates colonic motility and
decreases transit time
The osmotic agent lubiprostone is FDA
approved for constipation caused by IBS and
opioid-induced constipation in adults.
100. Several peripherally-acting mu-opioid receptor
antagonists (PAMORA) have been approved by
the FDA for opioid-induced constipation in
adults with chronic noncancer pain and/or for
palliative care (eg, naloxegol, methylnaltrexone,
naldemedine)
101. • Alvimopan:- PAMORA drug used for the tt of
postoperative ileus and constipation after
surgery.
• Linaclotide and plecanatide are indicated for
chronic idiopathic constipation & constipation
caused by IBS in adults.
102. Laxative abuse syndrome
With the use of strong purgatives, the colon
may be so thoroughly evacuated that a bowel
movement may not occur normally until a few
days later. This delay reinforces the need for
more laxative. Eventually the patient may
require daily laxatives to maintain bowel
function.