Approximately 100,000 people in the United States undergo ostomy surgery each year.1 Ileostomies, which may be temporary or permanent, are created for management of colon or rectal cancer, inflammatory bowel disease (ulcerative colitis, Crohn disease), trauma, diverticular disease, familial adenomatous polyposis, and congenital disorders such as Hirschsprung disease or imperforate anus.2 A diagnosis of short gut syndrome can be made when people are unable to maintain adequate nutrition and hydration due to small bowel length less than 150 to 200 centimeters.3 Short gut syndrome can result from multiple bowel resections due to Crohn disease, mesenteric ischemia, or surgical complications.3
Alterations in the anatomy of the gastrointestinal tract can affect the ability to absorb medication. The absorption of drugs is influenced by the type of stoma, residual length of the small bowel, quality of small bowel mucosa, nature and volume of stoma output, intestinal transit time, and formulation and dose of medication.4,5 The majority of medication absorption occurs in the upper small intestine, whereas the large intestine is responsible for absorption of slow-release medications.4 When drugs are taken by people with jejunostomies and ileostomies, the medications are processed differently than in people with an intact gastrointestinal tract. People who have significant portions of the small intestine resected are at risk of short gut syndrome.4 Because medication is absorbed through the lumen of the gastrointestinal tract, the decreased length of the bowel influences these patients’ responses to drugs. Underlying disease, such as Crohn disease, may cause inflammation and stricturing in the gastrointestinal tract, which further impacts drug absorption.4 Transit time through the stoma may also influence the rate of absorption of drugs.4
Medications that do not dissolve quickly may not be adequately absorbed and utilized in a shortened gastrointestinal tract, making these medications ineffective. Medications that may not be absorbed adequately include certain antimicrobial agents, digoxin, mesalazine, levothyroxine, and oral contraceptives.5 Enteric-coated or extended-release medications should be avoided by those with an ileostomy because the medication is absorbed or partially absorbed in the colon.6,7
At the time of ostomy surgery or an extensive bowel resection, patients and/or parents of children need to be educated about the effect the surgery will have on medication absorption. When taking medications, people living with a fecal stoma or those with short gut syndrome should monitor the output of the ostomy pouch for undissolved pills or capsules.6 If residual drug is noted, the health care provider or a pharmacist must be notified to discuss the need to change medication(s) or modify method(s) of administration for improved absorption.6
When prescribing medication, it is essential for health care professionals to understand the factors affecting absorption.5 A study conducted by Moore5 found that many hospital physicians and nurse practitioners did not evaluate patients’ bowel integrity and were not familiar with which medication may not be absorbed well by those with alterations in their gastrointestinal tract. Patients with medical conditions such as epilepsy, chronic pain, Parkinson disease, and cardiac disease, as well as those taking multiple medications, require detailed evaluation of their body’s ability to absorb medication.5 To assure proper absorption, medications can be prescribed in alternative forms such as liquid, soluble tablet, transdermal patch, sublingual, buccal, or parenteral.5,7 Levels of certain drugs, such as digoxin or lithium, should be monitored for efficacy of the dosage.5 The effectiveness of drug absorption can also be monitored by the medication’s response.5 Medications may need to be prescribed above the recommended dose to achieve a therapeutic range.5 Diuretics should be prescribed with caution because they can lead to dehydration and hypokalemia.7 Those with an ileostomy or short gut syndrome should avoid laxatives due to the potential for dehydration and electrolyte abnormalities.5
People living with short gut syndrome or a small bowel stoma, such a jejunostomy or an ileostomy, may find it necessary to advocate for themselves during interactions with the health care system. It is essential for these people to make sure that the health care provider is aware of their bowel anatomy. Any concerns people have regarding their medications should be discussed with their health care provider(s) or pharmacist. Conversely, health care professionals should be aware that patients may or may not be informed about how their conditions can affect medication absorption. Because bowel integrity may be altered early in a person’s life, patients may not be aware of their decreased ability to absorb drugs. It is essential for all providers to ask patients whether they have had previous intestinal surgeries and have a fecal stoma and, if so, to monitor the effectiveness of the medication(s).