Case Study
Initial Presentation
A 72-year-old man with history of rectal adenocarcinoma stage T4bN2 status post low anterior resection (LAR) with diverting loop ileostomy and neoadjuvant chemoradiation presented to the hospital with a 3-day history of nausea, vomiting, fatigue, and productive cough.
Additional History
On further questioning, the patient also reported odynophagia and dysphagia related to thrush. Because of his decreased oral intake, he stopped taking his usual insulin regimen prior to admission. His cancer treatment course was notable for a LAR with diverting loop ileostomy which was performed 5 months prior. He had also completed 3 out of 8 cycles of capecitabine and oxaliplatin-based therapy 2 weeks prior to this presentation.
Physical Examination
Significant physical examination findings included dry mucous membranes, oropharyngeal candidiasis, tachycardia, clear lungs, hypoactive bowel sounds, nontender, non-distended abdomen, and a right lower abdominal ileostomy bag with semi-formed stool.
Laboratory test results were pertinent for diabetic ketoacidosis (DKA) with an anion gap of 33, lactic acidosis, acute kidney injury (creatinine 2.7 mg/dL from a baseline of 1.0) and blood glucose of 1059 mg/dL. Remainder of complete blood count and complete metabolic panel were unremarkable.
Hospital Course
The patient was treated for oropharyngeal candidiasis with fluconazole, started on an insulin drip and given intravenous fluids (IVFs) with subsequent resolution of DKA. Once the DKA resolved, his diet was advanced to a mechanical soft, moderate calorie, consistent carbohydrate diet (2000 calories allowed daily with all foods chopped, pureed or cooked, and all meals containing nearly equal amounts of carbohydrates). He was also given Boost supplementation 3 times per day, and daily weights were recorded while assessing for fluid losses. However, during his hospital course the patient developed increasing ileostomy output ranging from 2.7 to 6.5 L per day that only improved when he stopped eating by mouth (NPO).
What conditions should be evaluated prior to starting therapy for high-output enterostomy/diarrhea from either functional or structural SBS?
Prior to starting anti-diarrheal and anti-secretory therapy, infectious and metabolic etiologies for high-enterostomy output should be ruled out. Depending on the patient’s risk factors (eg, recent sick contacts, travel) and whether they are immunocompetent versus immunosuppressed, infectious studies should be obtained. In this patient, Clostridium difficile, stool culture, Giardia antigen, stool ova and parasites were all negative. Additional metabolic labs including thyroid-stimulating hormone, fecal elastase, and fecal fat were obtained and were all within normal limits. In this particular scenario, fecal fat was obtained while he was NPO. Testing for fat malabsorption and pancreatic insufficiency in a patient that is consuming less than 100 grams of fat per day can result in a false-negative outcome, however, and was not an appropriate test in this patient.
Hospital Course Continued
Once infectious etiologies were ruled out, the patient was started on anti-diarrheal medication consisting of loperamide 2 mg every 6 hours and oral pantoprazole 40 mg once per day. The primary internal medicine team speculated that the Boost supplementation may be contributing to the diarrhea because of its hyperosmolar concentration and wanted to discontinue it, but because the patient had protein-calorie malnutrition the dietician recommended continuing Boost supplementation. The primary internal medicine team also encouraged the patient to drink Gatorade with each meal with the approval from the dietician.
What are key dietary recommendations to help reduce high-output enterostomy/diarrhea?
Dietary recommendations are often quite variable depending on the intestinal anatomy (specifically, whether the colon is intact or absent), comorbidities such as renal disease, and severity of fluid and nutrient loses. This patient has the majority of his colon remaining; however, fluid and nutrients are being diverted away from his colon because he has a loop ileostomy. To reduce enterostomy output, it is generally recommended that liquids be consumed separately from solids, and that oral rehydration solutions (ORS) should replace most hyperosmolar and hypoosmolar liquids. Although these recommendations are commonly used, there is sparse data to suggest separating liquids from solids in a medically stable patient with SBS is indeed necessary [6]. In our patient, however, because he has not yet reached medical stability, it would be reasonable to separate the consumption of liquids from solids. The solid component of a SBS diet should consist mainly of protein and carbohydrates, with limited intake of simple sugars and sugar alcohols. If the colon remains intact, it is particularly important to limit fats to less than 30% of the daily caloric intake, to consume a low-oxalate diet, supplement with oral calcium to reduce the risk of calcium-oxalate nephrolithiasis, and increase dietary fiber intake as tolerated. Soluble fiber is fermented by colonic bacteria into short-chain fatty acids (SCFAs) and serve as an additional energy source [7,8]. Medium-chain triglycerides (MCTs) are good sources of fat because the body is able to absorb them into the bloodstream without the use of intestinal lymphatics, which may be damaged or absent in those with intestinal failure. For this particular patient, he would have benefitted from initiation of ORS and counseled to sip on it throughout the day while limiting liquid consumption during meals. He should have also been advised to limit plain Gatorade and Boost as they are both hyperosmolar liquid formulations and can worsen diarrhea. If the patient was unable to tolerate the taste of standard ORS formulations, or the hospital did not have any ORS on formulary, sugar, salt and water at specific amounts may be added to create a homemade ORS. In summary, this patient would have likely tolerated protein in solid form better than liquid protein supplementation.