An ostomy, or stoma, is a surgically created opening on the abdomen that allows stool or urine to exit the body into an external pouch. This procedure is performed when a section of the bowel or urinary tract is diseased or needs to be bypassed. A high output stoma (HOS) is a significant complication where the volume of fluid draining from the stoma is excessive. This high fluid loss places the individual at immediate risk of dehydration and nutritional deficiencies because the body struggles to maintain the necessary balance of water and dissolved minerals.
Understanding the Volume Thresholds
The classification of a high output stoma is based on the volume of fluid produced over a 24-hour period. A sustained output exceeding 1,500 to 2,000 milliliters (mL) per day for an ileostomy or jejunostomy is generally considered high output. For colostomies, an output greater than 1,000 mL in 24 hours is often used as the threshold for concern.
A normal, established ileostomy typically produces an output of about 500 to 1,200 mL per day. It is important to differentiate between a temporary spike in output, such as from a short-term illness, and a sustained high output requiring medical intervention. Ileostomies and jejunostomies are much more prone to high output than colostomies because they bypass the large intestine’s water-absorbing function. The larger and more watery the effluent, the greater the threat to the patient’s fluid and electrolyte status.
Factors That Increase Stoma Output
The excessive fluid loss characteristic of a high output stoma is traced to factors that disrupt the bowel’s absorption processes. A major anatomical cause is short bowel syndrome, resulting from the surgical removal of a large amount of the small intestine. When less than 100 to 200 centimeters of small bowel remains, the reduced absorptive surface area leads directly to malabsorption and high effluent volume.
Underlying disease activity, such as active Crohn’s disease or enteritis (inflammation of the small intestine), can also cause a significant increase in output. Inflammation impairs the bowel lining’s ability to absorb nutrients and water, resulting in their rapid passage through the digestive tract. Partial bowel obstruction or internal fistulas may also contribute to the complication.
Dietary choices play a substantial role, as highly sugary or high-osmolarity foods and beverages pull water into the bowel lumen, increasing the output. Examples include fruit juices, regular sodas, and sports drinks that lack the proper sodium-to-sugar ratio. Certain medications, including laxatives and some antibiotics, can also stimulate bowel motility, leading to a temporary or sustained increase in fluid production.
Recognizing Dehydration and Electrolyte Imbalance
A sustained high output stoma causes a rapid loss of water and electrolytes, particularly sodium and potassium. Since ileostomy and jejunostomy effluent is rich in sodium, large volumes quickly lead to sodium depletion. This loss results in dehydration, which may escalate into acute kidney injury if not addressed promptly.
The body signals this depletion through warning signs that patients should monitor closely. Excessive thirst and a dry mouth or tongue are the earliest indicators of dehydration. As the condition worsens, the individual may experience lightheadedness or dizziness, especially when standing up, due to low blood pressure.
Electrolyte imbalance manifests through symptoms like muscle cramps, fatigue, and lethargy. Decreased frequency of urination or the production of very dark, concentrated urine signals that the kidneys are attempting to conserve fluid. Changes in mental status, such as confusion, indicate a severe stage of dehydration that necessitates immediate medical attention and often intravenous fluid replacement.
Nutritional and Medical Management
Dietary and Fluid Management
Management focuses on reducing effluent volume and replacing lost electrolytes and fluid to promote absorption. Nutritional strategies involve modifying the diet to include foods that help thicken the output, such as starchy carbohydrates like rice, pasta, and potatoes. These foods are easier for the remaining bowel to absorb and give the stool a more solid consistency.
Fluid intake must be carefully managed, as drinking large amounts of plain water or hypotonic fluids can paradoxically increase stoma output and worsen dehydration. Patients are advised to restrict hypotonic fluids (water, tea, coffee) to a small daily limit. Fluid requirements should be met by sipping specialized oral rehydration solutions (ORS) that contain a precise balance of sodium, glucose, and water, optimizing absorption in the small intestine.
Pharmacological Intervention
Pharmacological intervention typically involves anti-motility medications to slow gut contents, allowing more time for fluid and nutrient absorption. Loperamide is a common medication used to decrease bowel transit time, often prescribed in higher doses than usual. In severe cases, codeine phosphate may be added, or octreotide injection may be considered to reduce intestinal secretions. Regular monitoring of serum electrolytes guides replacement therapy, which may require intravenous fluids in cases of severe depletion.