What is well known about
constipation
• What are the common causes of chronic constipation ?
1. Lifestyle factors
2. Systemic illnesses, drugs
3. Physiological abnormalities- slow transit constipation and fecal evacuation disorders (pelivc floor
dyssynergia)
• Structural and physiological abnormalities
1. Anatomical luminal narrowing
2. Colonic hypomotility
3. Anal sphincter disturbances
4. And /or pelvic floor issues
Level 1 ….investigation ....discuss with patient
• Benign nature of the disease
• Balanced diet(fibre) , adequate hydration
• Regular time of defecation
(not to skip breakfast)
• Preference of Indian vs Western closet…
• Sort out psychological factors ...60%
Depression ,anxiety and somatization)
. psychotherapy /behavioral therapy
. stress management
• Patient not responding to dietary and lifestyle modification
• Inspection of anus and the perianal region
(Skin excoriation, hemorrhoids, fissure, fistula, prolapse of rectum )
Perianal sensation and anocutaneous reflux
(Brisk contraction of perianal skin ,anoderm and external anal sphincter)
Digital palpation of rectum
(Mucosa ,adjacent muscle, tenderness, mass, rectocele, stricture, stool
consistency)
Maneuvers to assess anorectal function
Assess: resting sphincter tone , anal canal length, anorectal angle, defect in anal
sphincter
Assess ….squeeze anal sphinter pressure
For FED/PFD: Left hand is placed over the lower abdomen and patient is asked to
bear down as if to defecate
Evaluate : push effort of abdominal muscles
Relaxation or contraction of anal sphincter and puborectalis
Degree of perineal descent
Rectal mucosal intussusception or prolapse
On completion look for the blood on gloved fingers
Colonic transit study ….simple non invasive
test
• Interpretation
1. Normal transit
2. Slow transit
3. Fecal evacuation disorder /pelvic floor dysfunction
ANO-RECTAL MANOMETRY –GOLD STANDARD
• Provides information on
Rectal sensation and compliance
Pressure activity in rectum and anal sphincter
Step 1 : Sensory threshold of rectum
• Ballon distension : measures rectal sensitivity
• Rectal ballon manually inflated :
2.5 ml /sec with a hand held syringe
• Perceived sensations : sensory thresholds
1. First sensation
2. Desire to defecate
3. Urgency
4. Maximum tolerance or presence of pain
Step 2 : Balloon expulsion test
• Simple bedside assessment for expulsion of a simulated stool
• Balloon filled with 25/50 ml of warm water or air
• Mild traction is given
• Time taken to expel balloon …left lateral position ...non physiological
• Normal : 1 to 5 mins
• Expulsion time beyond 5 mins – pelvic floor dyssynergia
Obstructive Defecation syndrome
• Clinically :
• Urge to defecate but unsuccessful fecal evacuation attempts
• Feeling of incomplete evacuation
• Excessive straining
• Lower abdominal pain
• Bleeding after defecation
• H/O digital rectal evacuation
Role of Dynamic MR Defecography
• Non invasive test …fast MR imaging
1. Images at various stages of defecation
2. Insight into pelvic muscle and rectal function
• Dynamic sequences consists of images during
Rest
Squeeze
Straining
Defecation
• Straining phase (pre rectal filling)
• Defecation phase (post rectal filling )
• Objective diagnostic tool in patients with surgical pelvic floor
dysfunction (PFD)
• Grades various forms of PFD
• Differentiates pelvic floor relaxation and pelvic organ prolapse
• Grading of the pelvic organ prolapse
PCL (pubococcygeal line), representing the level
of the pelvic floor;
H-line (puborectal hiatus line), representing the
anteroposterior hiatal
dimension, allowing the grading of the maximal
widening of the pelvis sling during straining;
M-line (muscular pelvic floor relaxation) measures the
pelvic floor descent from
the PCL line during straining.
MR-DEFECOGRAPHY
• Significant structural abnormalities associated with ODS - may
benefit from surgical intervention
Stapled transanal resection of rectum (STARR)
• No significant structural abnormalities….Respond to biofeedback
therapy
Role of Anorectal Endoultrasound
• Well tolerated and sensitive means of detecting structural integrity of
the internal and external sphincter
• Predicts therapeautic response to sphincteroplasty
• 3D EUS : new modality ….few added advantage over standered rectal
ultrasound
Summary
• Physiological causes for chronic constipation
• Abnormalities in colonic transit
• Abnormalities in defecatory process (pelvic floor dysynergia)…FED
• Combination of both ...transit and defaecatory precess
• Tests for
• Colonic transit : slitz marker study
• Fecal evacuation disorder : ARM, Balloon expulsion test and MR
Defaecography
• TREATMENT OF CONSTIPATION
• Customized for each individual Etiology/Age/Comorbidity/underlying
pathophysiology
• Patient's concerns and expectations
• Treatment:
• Lifestyle changes. Regular and nonstrenuous exercises.
• Adequate water intake(2-3L/d).
• Regular dedicated time for defecation (conditioned reflex),
• Healthy sleeping pattern and defecation in squatting posture.
• Avoid postponing defecation.
• Optimum time for evacuation is within 2 hrs after awakening/
breakfast.
• Time toilet training:
• Attempted defecation for 5 minutes at least twice per day.
• Within 60 minutes after meals.
• "push effort" 5-7 on the scale of 10.
• Exercise: -
• Shortens GI transit time.
• Increases number of propagated colonic contractions. –
• Geriatric or bad ridden patient/ sedentary lifestyle- increases risk of
constipation.
• DIET AND FIBRE –
• 30g/day is optimum dose.
• - Bran, prunes and psyllium: hold water, resist digestion and absorption in GI
tract.
• - Soluble fibre (isapaghula) causes less gas / bloating than insoluble dietary fibres.
• - Increase stool weight.
• - Accelerated colon transit time.
• - Constipated patient with slow transit or pelvic floor dysfunction respond poorly.
• - Constipation without underlying motility disorder improved.
• - Insufficient data to recommend synthetic polysaccharide methylcellulose or
calcium polycarbophil or bran.
• Benefit will be apparent after weeks. Generous water intake is required,
otherwise stool becomes hard, bulky and difficult to expel.
• R/O obstruction / gastroparesis / fecal impaction in bed redden patient or those
with limited fluid intake.
PHARMACOLOGICAL AGENTS
• Stool softeners:
• c- Sodium (Cusena) and Calcium docusate compounds
• Anionic surfactant
• Lower surface tension of stool
• Facilitate mixing of aqueous and fatty substance
• Stimulate intestinal fluid secretion
• Mineral oil provides lubrication by emulsifying stool mass
• Side effects of mineral oil are aspiration, fat soluble vitamin
malabsorption, foreign body reactions and fecal incontinence
STIMULANT LAXATIVES
• It consists of anthroquinolones (like Serena, cascara sagrada,
danthron, casanthrol)
• Diphenylmethane derivatives like bisacodyl, sodium picosulfate
• Ricinoleic acid like castor oil
• Stimulant laxatives affect electrolyte transfer across mucosa and
enhance colonic transport and motility
• Anthroquinones increase fluid and electrolyte secretion in the small
intestine: increase colonic motor activity, cause melanosis coli.
• Side effect: Abdominal discomfort, cramp, fecal incontinence
• Best suited for short term use
• OSMOTIC LAXATIVE
• Salts of Magnesium phosphate and sulfate
• Poorly absorbed synthetic disaccharides like lactulose, sugar alcohol like sorbitol
or mannitol.
• Inert polymer: Polyethylene Glycol. PEG 3350.
Osmotic laxatives include ions or molecules not well absorbed by the intestine,
causing retention of water within lumen to maintain osmotic balance with plasma
• Magnesium salts - Milk of magnesia or Mg citrate carbonated drink.
• Sulfate and phosphate compound -hyperosmolar agents. Phosphate salts used as
enema.
• Lactulose: synthetic disaccharide that cannot be hydrolyzed and serves as an
osmotic agent. Sorbitol and mannitol act similarly.Glycerine suppository also
works as an osmotic agent
• Polyethylene Glycol (PEG 3350): Large polymer, poorly absorbed, metabolically
inert, not degraded by bacteria. 68 g of PEG results in good laxation.
EFFICACY OF COMBINATION OF LAXATIVES AN INDIAN STUDY:
• Milk of Magnesia + Liquid Paraffin + Sodium Picosulphate
combination given for 4 weeks
Results: .
• Stool frequency: improved significantly
• Straining during defecation: reduced by 28%
• Stool consistency: improved (significantly in patients of constipation
with obstructive defecation syndrome and anal fissure)
• 50% patients: significantly improved, 50% patients somewhat
improved 0% patients: worsened/unchanged (Physician's global
efficacy assessment)
• All patients showed good adherence with better safety & tolerability.
• CHOOSING THE SAFE AND EFFECTIVE LAXATIVE
Thus,
• Combination Laxatives like Milk of Magnesia+ Liquid Paraffin
+Sodium Picosulphate, that combine the benefits of all the three
types of Laxatives may be optimal choice:
• Osmotic: Softer Stools
• Stimulant: Fastest Onset of Action, Increased Peristalsis
• Lubricant: Reduced Resistance to Stool Passage
• SEROTONERGIC AGENTS: PRUCALOPRIDE - 5HT4 agonist.
• Peak plasma time 2 — 3 hrs.
• Bioavailability 90%. Reasonably well tolerated.
• 90% of Serotonin receptors are in GI tract.
• Stimulation of 5HT4 receptors - promotes peristalsis (high amplitude
propagating contractions HAPC),
• Induces Chloride secretion
• Reduces visceral hypersensitivity.
• Dose 2 mg for age group < 65 and 1mg for > 65.
• Side effects: headache, abdominal pain, diarrhoea, nausea.
• Monitor for worsening of depression, emergence of suicidal thoughts.
CHLORIDE CHANNEL, ACTIVATORS: /LUBILPROSTONE Chloride channel located in
the apical/ serosal membrane of enterocytes and facilitate Chloride transport.
• Lubiprostone:
• 01 targeted bicyclic fatty acid.
• Selectively activates type-2 Chloride channels.
• Increases secretion of negatively charged chlorides by enterocytes.
• This results in excretion of Sodium and water into lumen to maintain enterocyto
electrical gradient; increased fluid secretion, intestinal motility and stool
transport
• 24 mg twice daily.
• Side effect: nausea, diarrhea, headache.
• Unsafe during pregnancy: category C.
GUANYLATE CYCLASE C AGONIST (GCC): LINACLOTIDE • Activates Chloride
secretion, alters binding to ()CC - Guanylate Cyclase C agonist and accelerates
colonic transit.
• TREATMENT OF EVACUATION DISORDERS :Behavioral approaches
using neuromuscular conditioning are effective in managing
dyssynergic defecation.
Dyssynergic defecation:
• Commonest functional constipation disorder defined by incomplete
evacuation of feces due to paradoxical contraction or failure of
relaxation of pelvic floor muscles while straining to defecate.
• No morphological or neurological abnormalities.
• Believed to be behavioral disorder.
Treatment of dyssynergic defecation:
- Diet
• - Laxative
• - Timed toilet training
• - Neuromuscular conditioning by using biofeedback techniques
• - Botulinum toxin injection between sphincters, myomectomy,
surgery
BIOFEEDBACK THERAPY
• Instrument based behavioral program
• Principle: Any behavior, when reinforced, likelihood of being
repeated and perfected increase several fold (helmet, seatbelts)
- To correct the incoordination or dyssynergic behavior during
defecation
- Restore normal coordination of diaphragm, abdominal, rectal,
puborectalis and anal sphincter
- To improve rectal sensory perception
Rectoanal coordination training
• Diaphragmatic muscle training with stimulated defectaion
• Manometry guided pelvic floor training
• Simulated defecation training
• Technique
- Placement of manometry or electromyography probe into anorectum
- Signals from probe are displayed on a monitor during defecation providing visual feedback
- For simulated defecation, a waterfilled balloon is placed in the rectum
- Patient is trained to expel the balloon by coordinating contraction of abdominal muscles, diaphragm and relaxation of pelvic muscles
- Diaphragmatic breathing facilitates defecation
- Posture
Symptomatic improvement is reported up to 80%
• Technique
- Placement of manometry or electromyography probe into anorectum
- Signals from probe are displayed on a monitor during defecation providing visual feedback
- For simulated defecation, a water filled balloon is placed in the rectum
- Patient is trained to expel the balloon by coordinating contraction of abdominal muscles, diaphragm and relaxation of pelvic
muscles
- Diaphragmatic breathing facilitates defecation
- Posture
Symptomatic improvement is reported up to 80%
Treatment of Dyssynergic defecation
• Sensory training:
• Patients with dysynergic defecation have impaired rectal sensation.
• Rectal sensory training provides additional benefit.
• Simulated defecation training - a waterfilled balloon is placed in the rectum.
• Posture and breathing technique is monitored while patient attempts to expel balloon.
• For reinforcement therapist may pull on the balloon.
• Adequate relief after 3 months is noted in 71% for biofeedback, 33% for placebo and 20% for diazepam.
• Labour intensive programme hence not widely available.