1. Management of Constipation in Adults
Grace Lee
May 2018

2. Objectives Learn how to define constipation
Learn the causes of constipation
Learn how to manage constipation

3. Case
A 76 year old woman with HTN, DMII, HLD presents to your clinic to be evaluated for constipation, which has been ongoing for the past year. She’s complaining of having stools only twice a week and has to strain for nearly all of her bowel movements. She has been eating more vegetables, drinking more water, and increasing her physical activity. She has also recently included Metamucil in her diet. Her last colonoscopy one year ago was normal. What would you offer next for her constipation?
A. Miralax
B. Senna
C. Docusate
D. Weekly tap water enemas
E. Either A. or B.

4. Definition Rome IV criteria (Need 2 of the following): Straining*
Lumpy or Hard Stools*
Sensation of Incomplete Evacuation*
Use of Manual Maneuvers (digital evacuation)*
Sensation of Anorectal Obstruction/Blockage*
< 3 Bowel Movements per week
-Those with * next to them, need to be associated with >25% of defecations
* Need to be associated with >25% of defecations

5. Causes Primary/Functional Secondary Causes
-A thorough history is needed to elicit the etiology of constipation
-You always want to rule out secondary causes of constipation first

6. Primary/Functional There are 3 subtypes: Normal transit/Psychiatric
Slow transit = due to enteric nerve plexus dysfunction
Dyssynergic defecation = inability to relax muscles to allow bowel movements out from rectum
-Normal transit: Normal colonic motility
= This is often due to the belief of having decreased bowel movements, i.e. psychiatric
-Slow transit: Patients have little or no increase in motility after eating

7. Secondary Causes Neurogenic Non-neurogenic Irritable Bowel Syndrome
Central: Multiple Sclerosis, Parkinson Disease
Peripheral: DM II, Hirschsprung Disease
Irritable Bowel Syndrome
Drugs
Analgesics: NSAIDs
Anti-cholinergics: Anti-histamines, antipsychotics,
anti-depressants (TCA)
Cation-containing agents: Iron, Antacids
Neurally active: Opiates, Serotonin Antagonists (Zofran), Antihypertensives (CCB, Beta-blockers)
Non-neurogenic
Hypothyroidism, metabolic (i.e. hypokalemia,
hypercalcemia), CKD, Rheum disorders, IBD
Other Examples:
Neurogenic:
a) Central – Spinal cord injury
b) Peripheral – Autonomic neuropathy, Chagas Disease, Intestinal Pseudo-obstruction
Drugs:
- Anti-cholinergics: Anti-histamines (Claritin, Zyrtec, Allegra), Antidepressants (TCA), Anti-epileptics
- Cation-containing agents: Sucralfate, Barium
- Neurally active agents: Ganglionic blockers, Vinca alkaloids
Non-neurogenic: Rheumatologic disorders (dermatomyositis, scleroderma), anorexia nervosa, pregnancy, panhypopituitarism, myotonic dystrophy, obstructing lesions of GI tract (colon CA)

8. Management

9. Steps in Management Lifestyle Changes & Bulk-Forming Laxatives
Other Laxatives: Surfactants, Osmotic or Stimulant Laxatives
Suppositories
-Order of management of constipation
Fecal Disimpaction & Enemas
Other Pharmacologic Agents

10. Step 1: Lifestyle Changes & Bulk-Forming Laxatives
Lifestyle modification
Increase fluids, fiber, and physical activity
Bulk-forming laxatives: Absorb water & soften stool
Psyllium
(Metamucil)
Methylcellulose (Citrucel)
Polycarbophil (FiberCon)
Wheat Dextrin (Benefiber)
-Lifestyle changes and bulk-forming laxatives are the first step in management of constipation
-Recommended daily dietary fiber: grams/day

11. Step 2: Other Laxatives Mush or Push Osmotic Laxatives
Stimulant Laxatives
Surfactants

12. Step 2: Surfactants
Decrease surface tension of stool, allowing water to enter stool more easily
Example:
Docusate/Colace
-There is little evidence to support use of surfactant agents in chronic constipation -> in other words, don’t use it
-Less effective than other laxatives

13. Step 2: Osmotic Laxatives
Draw water into lumen by osmosis & soften stool (mush)
Examples:
Polyethylene glycol (PEG)
Synthetic Disaccharides
Lactulose, Sorbitol
Saline
Milk of Magnesium, Magnesium Citrate
-PEG examples: Golytely, Miralax
-PEG based laxatives are superior to synthetic disaccharide based laxatives as lactulose & sorbitol can lead to abdominal bloating & flatulence

14. Step 2: Stimulant Laxatives
Increase intestinal motor activity by activating enteric nerves (push)
Examples:
Senna
Bisacodyl
-Good for slow-transit constipation

15. Step 3: Suppositories
Liquify stool at rectum, allowing it to pass easier
Examples:
Bisacodyl
Glycerin
-If laxatives fail, then suppositories can be trialed

16. Step 4: Fecal Disimpaction & Enemas
1st Step: Manual disimpaction
2nd Step: Use mineral oil enema for lubrication
3rd Step: Cleanse bowel with other enemas
Warm water
Soap Suds
Sodium phosphate (Fleet)
4th Step: Administer water-soluble contrast enema (in fluoroscopy suite)
-If the patient has failed diet/lifestyle changes, laxatives, and suppositories, then think of fecal disimpaction as a reason for constipation
-1st step: manual disimpaction should be attempted first
-2nd step: once manual disimpaction is completed, then a mineral oil enema can be given to provide lubrication & soften the stool
-3rd step: once a mineral oil enema is given, then you want to cleanse the bowel with other enemas (preferred regimen: warm water enema x3 days)
= Avoid sodium phosphate enemas in the elderly as it can lead to dehydration
-4th step: If fecal impaction is unsuccessful or partially successful, then a water-soluble contrast enema is used (Gastrografin or Hypaque) to identify other reasons why a patient is constipated -> shows you the entire colon & rectum
= How it works:
1) An X-ray is taken prior to administration of enema
2) Then, the enema is administered
3) Then, additional x-rays are taken in real-time as the enema fills your colon to see any abnormalities in your colon or rectum

17. Suppositories & Enemas: Where do they work?
Lactulose Enema
Tap Water Enema
Soap Sud Enema
-Diagram depicting where suppositories and enemas work
-Water-soluble contrast enema is the only one that reaches the right side of the colon
Fleet Enema
Water-soluble Contrast Enema
Suppositories
Mineral oil Enema

18. Step 5: Other pharmacologic agents
Increase fluid secretion into lumen & motility
Guanylate cyclase C receptor agonists
Linaclotide
Plecanatide
Cl channel activator
Lubiprostone
-Some examples of other pharmacologic agents available for severe constipation if previous regimens fail
-Both Guanylate cyclase C receptor agonists and Cl channel activators work by increasing secretion of fluid into lumen of GI tract and increase motility

19. Back to the Case
A 76 year old woman with HTN, DMII, HLD presents to your clinic to be evaluated for constipation, which has been ongoing for the past year. She’s complaining of having stools only twice a week and has to strain for nearly all of her bowel movements. She has been eating more vegetables, drinking more water, and increasing her physical activity. She has also recently included Metamucil in her diet. Her last colonoscopy one year ago was normal. What would you offer next for her constipation?
A. Miralax
B. Senna
C. Docusate
D. Weekly tap water enemas
E. Either A. or B.
1) Does this patient have constipation?
= Yes since she fulfills at least 2 of Rome IV criteria: <3 bowel movements/week and has to strain for >25% of defecations
2) What has she done to try to relieve her constipation?
= Increased fluids, fiber (vegetables) in her diet, and physical activity
= Added Metamucil (bulk-forming laxative)

20. The Answer
A 76 year old woman with HTN, DMII, HLD presents to your clinic to be evaluated for constipation, which has been ongoing for the past year. She’s complaining of having stools only twice a week and has to strain for nearly all of her bowel movements. She has been eating more vegetables, drinking more water, and increasing her physical activity. She has also recently included Metamucil in her diet. Her last colonoscopy one year ago was normal. What would you offer next for her constipation?
A. Miralax
B. Senna
C. Docusate
D. Weekly tap water enemas
E. Either A. or B.
Answer is E. After the patient increases her fluid intake, changes her diet, increases her physical activity, and has added bulk-forming laxatives, either osmotic or stimulant laxatives can be added to her regimen
Why not the other choices?
A. Miralax is an osmotic laxative and is a good option to add to her current regimen, but Senna can also be added as the next choice
B. Senna is a stimulant laxative and is a good option to add to her current regimen, but Miralax can also added as the next choice
C. Docusate is a surfactant/stool softener with minimal effects on chronic constipation, so this would not be a good option to add to her current regimen
D. Tap water enemas would be given only after both osmotic and stimulant laxatives have been trialed with no improvement

21. Summary
A thorough history must be obtained to rule out secondary causes of constipation
Dietary/lifestyle changes & Bulk-forming laxatives should be used first
Then, osmotic/stimulating laxatives can be used
If all laxatives fail, then suppositories and enemas are used
Finally, other pharmacologic agents are used if all else fails

22. References
Text:
Wald, A. Etiology and evaluation of chronic constipation in adults. Uptodate.com. May 2018.
Wald, A. Management of chronic constipation in older adults. Uptodate.com. May 2018.

23. References
Images:
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Edelman, J. (2017). Can Your Baby's Poop Reveal How Smart They'll Be? Apparently [Digital Image]. Retrieved from
Izzy, M., et al (2016). Mechanism of action of lubiprostone [Digital Image]. Retrieved from
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Ternopil State Medical University (2018). Bulk Laxatives [Digital Image]. Retrieved from
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