Title: Chronic Constipation
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2Chronic constipation - an evidenced based
approach
- Robert A. Baldor, MD, FAAFP
- Professor, Family Medicine Community Health
- UMass Medical School
3Learning Objectives
- by the end of the session, you will have a clear
understanding of the basic pathophysiology
related to chronic constipation - and develop an evidenced based approach for the
primary care diagnosis and treatment of these
chronic problems.
4Mrs Z.
- A 34-year-old white female who complains of
constipation she hasnt discussed it in the past
as its embarrassing, but states that she has
been constipated her entire life and has tried a
variety of OTC products without much relief. - She further reports that she is very active, runs
4 days a week, that she always has a bottle of
water with her and tries to eat salads
regularly..
5History
- Character of the problem
- Consistency
- Frequency
- Straining, bloating
- Diarrhea
- Medications
6Mrs. Z
- Doesnt have much discomfort, but has to strain
and has hard stools along with blood occasionally
on TP she tends to go about twice a week - She will occasionally have diarrhea but it
seems related to something she had eaten - Takes Tums for her bones
7Constipation No Clear Definition
- A group of syndromes with similar findings
8Am College of Gastroenterology
- Unsatisfactory defecation, characterized by
infrequent stools and/or difficult stool passage - Brandt 2005
9Pathophysiology
- As food leaves stomach, gastroileal reflex
relaxes the ileocecal valve and digested food
(chyme) enters the colon - Peristaltic contractions move chyme through the
colon - Na actively absorbed - water follows because of
the generated osmotic gradient
10Normal Colonic Transit Time
- A meal reaches the ileo-cecal valve in 4 hours
- the sigmoid colon 12hours later
- then slows to the anus.
- Plastic pellets with a meal ? 70 recovered in 3
days remainder in a week!
11Defecation
- Food distends the stomach, initiating the
gastro-colic reflex causing rectal contractions
a desire to go! - Urge to defecate occurs as rectal pressures ?
- Defecation reflexes can be inhibited by
voluntarily contracting the external sphincter or
facilitated by straining - Pelvic floor/anal sphincter dysfunction interfere
with normal defecation
12Most with primary constipation suffer from which
one of the following?
- Slow colonic transit time
- Pelvic floor/anal sphincter dysfunction
- Functional normal transit time and sphincter
function
13Most with primary constipation suffer from which
one of the following?
- Slow colonic transit time
- Pelvic floor/anal sphincter dysfunction
- Functional normal transit time and sphincter
function
14Secondary Constipation
- Endocrine dysfunction (DM, hypothyroid)
- Metabolic disorder (? Ca,? K)
- Mechanical (obstruction, rectocele)
- Pregnancy
- Neurologic disorders (Hirschsprungs, multiple
sclerosis, spinal cord injuries)
15Medication Effect
- Anti-cholinergic effects
- Antidepressants
- Narcotics
- Antipsychotics
- Calcium channel blockers
- Antacids (calcium, aluminum)
- Mrs. Z taking Tums (ca carbonate) for
osteoporosis - ca phosphate (Posture) and ca
citrate (Citracal) less constipating.
16IBS ? Rome III Criteria
- Symptoms at least 3 days/month of recurrent
abdominal pain or discomfort associated with hard
constipated stools interrupted by brief episodes
of diarrhea - Drossman Gastroenterology. 2006
17IBS Treatment
- Multiple RCTs with inconsistent results best
evidence for treating IBS-C - Bulking agents
- Psychotropic agents
- DARE review 2001
18Red flags
- Onset after age of 50
- Hematochezia/melena
- Unintentional weight loss
- Anemia
- Neurological defects
19Physical Exam
- Digital rectal examination
- Stool character
- Pain, anal tone
- Masses, fissures, hemorrhoids,
- Abdominal/gynecological exam
- Masses, pain
- Neurological exam
20Treatment Behavioral
- Toileting program to take advantage of natural
reflexes - Obey the urge
- Gastro-colic
- Defecation reflex
21Medications - Laxatives
- Bulking agents
- Stool softeners
- Osmotic agents
- Stimulants
- Lubricants
- Other
22Bulking Agents at the Grocery Store
- Vegetables
- Fruits
- Whole grain foods
- Bran (hard outer layer of cereal grains)
- Bloating and gas can be problematic
- Gradually increase intake to 25 grams/day
- Less fermentable fiber like wheat bran tends to
be better tolerated
Limited evidence for effectiveness
23Food Serving Fiber (Gm)
All Bran cereal 1/3 cup 10
Whole wheat bread 2 slices 4
Wheat bran muffin medium 3
Brown rice 1cup 3
Apple/Pear medium 4
Banana medium 3
Dried figs 5 8
Prune juice 1 cup 3
Sunflower seeds ¼ cup 3
Baked potato w/skin medium 4
Canned baked beans ½ cup 5
Chickpeas ½ cup 5
Lentils/ Kidney beans ½ cup 8
Corn ½ cup 2
24Bulking Agents at the Pharmacy
- Moderate evidence
- Psyllium (Metamucil 2.5gms fiber/dose)
- Limited evidence
- Bran methycellulose (Citrucel 2gms fiber/dose)
- Polycarbophil (Fibercon)
- Fiber needs to be accompanied by adequate
amounts of liquid to be useful - 8oz/2-3gms of
added fiber!
25Stool Softeners Limited Evidence
- Contain docusate (Colace), an anionic detergent
with hydrophilic and hydrophobic ends that
improves the ability of water to mix with and
soften the stool - Helpful to soften stools to make defecation
easier (post-op, childbirth) - Helpful for hemorrhoids or anal fissures
- ? dose if no effect is seen after a week
- 40-400mg daily QD-QID
26Stimulants (Irritants)
- Irritate bowel, causing muscle contractions
- often in combination with ducosate
- work in 8-12 hrs (try qhs, increase to BID)
- Senna/ducosate (Senokot-S, Ex-lax - max 4/d)
- Bisacodyl/ducosate (Dulcolax, Correctol- max
30mg/d) - Casanthranol/ducosate (Peri-colace max 2/d)
27Stimulant Suppositories
- Contain bisacodyl/ducosate (Dulcolax)
- Glycerin suppositories also believed to have
their effect by irritating the rectum - Insertion of the suppository into the rectum may
itself stimulate a bowel movement
28Osmotic Laxatives
- Polyethylene glycol - PEG (good evidence)
- 17 grams daily
- Saccharines lactulose (moderate evidence)
- flatulence, bloating, cramping
- 15 - 120 ml qhs
- Sorbitol (effective as lactulose in elderly men)
- less bloating than lactulose
- 15 - 120 ml qhs
- Magnesium salts (MOM)
- avoid in renal insufficiency, best for acute
treatment
Lederle. ACP Journal Club, 1991.
29A Closer Look at Polyethylene Glycol - good
evidence for use
- PEG Large, chemically inert polymer, with
substantial osmotic activity - Bowel flora unable to metabolize
- Pulls water into colon to soften and increases
fecal bulk (takes 2-4 days to work) - First used in a balanced electrolyte solution for
colon cleansing (Golytely) - PEG 3350 (Miralax) or with electrolytes (Movical)
30Lubricant Laxatives
- Contain mineral oil (15-45 ml/day)
- Short-term use only
- Binds fat-soluble vitamins
- May decrease absorption of some drugs
- Avoid lubricants in those at risk for aspiration
(lipid pneumonia)
31Lubiprostone (Amitiza)
- Selective Chloride channel activator
- ? secretion of Cl- ions into small bowel Na and
water follow, resulting in a softer, bulkier
stool - 24 mcgs BID
- Nausea is common (32)
- Avoid use in pregnancy, breast-feeding
32Methylnaltrexone (Relistor)
- Methyl group reduces lipidophilic properties of
the opioid antagonist naltrexone - ? ability to
cross blood-brain barrier - Peripherally Acting Mu-Opioid Receptor (PAM-OR)
antagonist - Indicated for palliative care
- For short-term use (lt 4months)
- Side effects - abdominal pain and flatulence
33Other, Non-FDA Approved Agents, Act to Decrease
Transit Time
- Misoprostol (Cytotec 100-200mcg QID)
- a prostaglandin increases colonic motility1
- Colchicine (0.6mg qd - tid)
- neurogenic stimulation ? colonic motility 2
- 1.Roarty. Alimen pharm Therapeutics. 1997
- 2. Verne. Am J. Gastroenterology. 2003, Frame
J ABFP, 1998
34A Practical Approach
- R/O treatable secondary causes..
- Am Gastroenterological Assn (AGA) guidelines
- CBC, Glucose, TSH, calcium, creatinine
- Sigmoid/colonoscopy if red flags are present.
-
35Address Immediate Concerns
- Bloating/discomfort/straining
- Osmotic agent like PEG
- Post-op, childbirth, hemorrhoids, fissures
- Stool softener to make defecation easier
- Stimulants and suppositories acutely
- Manual disimpaction as needed
- then approach the chronic condition.
36Start with Lifestyle Changes
- Exercise, increase fluids and fiber to 25
grams/day over a period of 6 weeks. - Fiber must be accompanied by sufficient fluid
- Initial approach fruits and vegetables
- Add commercial bulking agents
- Obey the Urge!
- For children trial of rice vs cows milk
Uncontrolled studies support fiber for normal
transient constipation. Am J Gastroenterol. 1999
G Nutr 4/2010
37If No Improvement
- Add osmotic laxative
- adjust dose slowly until stools are soft
- take several days to work
- caution if CHF or renal insufficiency
- Add stimulant laxatives
- Lubiprostone
38Trial of Other Agents
- Misoprostol (Cytotec)
- Colchicine
- Refractory to empiric approach .
39Pursue Diagnostic Evaluation
- Colonoscopy if not indicated sooner .
- Barium enema for obstruction/megacolon
- Radiopaque Sitz-Markers to measure transit time
- markers ingested, KUB in 5 days
- retention gt20 markers indicates slow transit
- markers seen exclusively in distal colon/rectum
suggests pelvic floor dysfunction
40Referral to evaluate defecation.
- Balloon expulsion
- Defecography using a barium paste.
- Anorectal manometry with a rectal catheter
- Biofeedback with artificial silicon stool
- Surgery rarely indicated
Enck. Dig Dis Sci. 1993
41Summary.
- Constipation - unsatisfactory defecation, with
infrequent stools, difficult stool passage or
both - Functional constipation (normal transit time and
sphincter function) seen most often - Work-up is necessary in the presence of red flags
- onset gt50 yrs hematochezia/melena unintentional
weight loss anemia neurological defects - Best evidence for effectiveness is for osmotic
agents
42Long-term Laxative Concerns
- No evidence for addiction
- No evidence for tolerance
- No evidence for dependence
- No evidence for harm from stimulant use,
melanosis coli may develop, but it is a benign
condition - Muller-Lissner. Am J Gastroenterology. 2005
43The End!
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