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How to prevent and treat constipation

June 2015
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CONSTIPATION may sound mundane, but developing it in the hospital can add more than half a day and thousands of dollars to a patient’s stay. The good news is that there is a lot that hospitalists can do to prevent patients from experiencing this bothersome – and potentially dangerous – symptom in the first place and then to treat it quickly and effectively if it does occur.

Moreover, as hospitalists at this spring’s Society of Hospital Medicine annual conference heard from a gastroenterology and geriatrics specialist, hospitalists can handle much of that prophylaxis and treatment on their own and shouldn’t need subspecialist help, except for particularly complicated cases. Moreover, multidisciplinary teams can deliver constipation care successfully by following nurse-driven protocols.


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Patient education is key, said Brijen Shah, MD, assistant professor of medicine, GI, geriatrics and palliative medicine at the Icahn School of Medicine at New York’s Mount Sinai Hospital. When patients and families are educated about the topic, they end up being much more willing to try offered treatment or prophylaxis.

Dr. Shah also recommends that hospitalists include questions about a patient’s usual bowel habits at home during the admission process, asking not only about frequency but also about any straining or difficulty. Being in the hospital, he pointed out, usually worsens any baseline problem, and that knowledge can drive care plans and orders.

“You have to ask to know if it is really a problem for them,” Dr. Shah said. “And it’s not just asking about it when you suspect there is a problem.”

A protocolized approach
Dr. Shah presented an algorithm that he helped develop, which inpatient teams can follow when faced with a constipated patient. (More details about that recommendation is included in an article published in the January 2015 issue of Hospital Medicine Clinics.)


Recent Update: A constipation clinical pathway from Johns Hopkins All Children’s Hospital


The strategy begins with knowing whether the patient is on a constipation treatment regimen outside the hospital.

If the patient is not, first-line treatment can be 17 g of an osmotic-type laxative polyethylene glycol (PEG), frequently MiraLax, and 10 mg of the stimulant laxative oral bisacodyl (or 17.2 mg oral senna).

If, on the other hand, the patient uses an anticonstipation regimen at home, the algorithm recommends increasing the PEG dose to 34 g and giving the bisacodyl (10 mg) rectally. For either patient, the recommendation is to reassess after 24 hours and then either increase the medication or consider an additional workup to look for obstructions, distension, bleeding or another problem. If that still doesn’t work, hospitalists should consider giving the patient an enema “but only if the stool is in the rectum “or giving the patient a bowel preparation dose of magnesium citrate or PEG.

“If the rectal exam doesn’t show any stool or there is no impaction, I will skip giving the rectal therapy on the first try and just give a higher dose of MiraLax,” Dr. Shah said. Many non-GI experts make the mistake of quickly giving a patient a tap-water enema before the laxatives have a chance to work and bring the stool into the rectum, he said.

Hospitalists also need to do a physical exam, including a rectal exam, of a patient suffering from constipation or they may miss something important, such as impaction. Although abdominal X-rays should be taken only after a physical exam, he explained, they are useful “if you suspect that patients may have developed an ileus or you think there is stool throughout their colon.”

Common risk factors
Although many people think of constipation as a side effect of opioid medications that patients are taking for pain, Dr. Shah explained that other commonly prescribed medications have been shown to be even riskier.

These include antispasmodics, anticonvulsants, calcium supplements, antidepressants and antipsychotics. In addition, the patients most likely to develop inpatient constipation are those with diabetes, Parkinson’s disease, thyroid disease (more commonly hyperthyroidism than hypothyroidism), scleroderma, metabolic diseases, and spinal cord diseases including spinal cord injury, which physicians who work in VA hospitals see commonly. An article on the risk factors for chronic constipation was published in the May 2003 issue of The American Journal of Gastroenterology.

One caveat about diabetes as a risk factor: For some people, diabetes is associated with diarrhea rather than constipation.

Patients are also at higher risk for developing constipation in the hospital if they need intensive care, have had intra-abdominal surgery in the last week or have a history of outpatient constipation. For these patients and for those on high-risk medications, Dr. Shah recommended starting patients on prophylaxis such as 17 g of PEG and 5 mg of oral bisacodyl from admission. He further advised that these medications be given 30 minutes before breakfast “to take advantage of the migrating motor complex, which is the housekeeper function of our gut.”


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Dr. Shah also urged hospitalists to work with nurses to improve patients’ mobility. While the data in this area aren’t great, he noted, there is some evidence that “a lack of mobility is associated with constipation.”

While hospitalists can choose from a number of medications, Dr. Shah said the evidence is best with PEG osmotic-type laxatives and lactulose. There are fewer efficacy data for surfactant stool softeners like docusate sodium, fiber supplements and sennosides.

Physicians should also be aware of a handful of new, effective medications such as methlynaltrexone, lubiprostone and linaclotide. These are already being used in outpatient settings for irritable bowel syndrome or opioid-related constipation, he said.

And several other new medications, called PAMORAs (peripherally-acting mu-opioid receptor antagonists) are in the pipeline and “will be a nice option,” Dr. Shah said.

Treating constipation
Dr. Shah also offered these tips for hospitalists to treat patients with constipation:

  • Maximize one therapeutic regimen at a time. He recommends picking one medication “say, an osmotic-type laxative like MiraLax “and increase the dose over a few days before switching to a different agent or strategy. “Usually by the time we get called in for a consult,” Dr. Shah said, referring to his fellow GI subspecialists, “the patient has been on a little bit of three different types of bowel regimens. None of them is working very well but none has been maxed out.”
  • Do a rectal exam. Unfortunately, Dr. Shah said, there are times when he has been called for a problem that has gotten worse because no one did a rectal exam and, therefore, missed a serious problem like fecal impaction. In addition, a rectal exam can help you decide whether to order an enema.
  • But think twice before ordering an enema. Patients generally dislike receiving them and nurses hate giving them. Plus, an enema won’t work at all if there is no stool in the rectal vault but instead is building up in the colon.
  • Be mindful of patients with C. diff or ulcerative colitis. “If a patient had diarrhea but suddenly on rounds a day or two later, you hear that they didn’t have any output last night, you should worry about a megacolon,” Dr. Shah cautioned. “I would send the patient for an abdominal CT scan after doing an exam because you want to get those answers quickly.”
  • Pay attention to patient preference. Some patients can’t abide the side effects of some constipation therapies, such as bloating and flatulence (a side effect of psyllium) or abdominal cramping (a side effect associated with the stimulant laxative bisacodyl). Dr. Shah pointed to alternatives such as an herbal tea that contains Senna called Smooth Moves. Spending a little time on patient education, he said, will also prevent patients from quitting a prophylactic regimen you order.
  • Don’t be afraid to order a bowel prep if nothing else is working. Because it isn’t being used to completely clean out the bowel for a colonoscopy, said Dr. Shah, hospitalists shouldn’t change a patient’s diet to go along with the bowel prep. “Don’t make them NPO, but have them keep taking the bowel prep until they go. It is very effective.”

Deborah Gesensway is a freelance writer who covers U.S. health care from Toronto.

Published in the June 2015 issue of Today’s Hospitalist