Diarrhea in individuals with a stoma is often referred to as “high output.” A stoma is a surgically created opening on the abdomen that redirects waste from the digestive tract into an external pouch. While the consistency of stoma output naturally varies, persistent, watery, and high-volume output is a serious condition requiring prompt attention. This excessive discharge causes rapid loss of fluid and essential electrolytes, dramatically increasing the risk of severe dehydration and dangerous imbalances, particularly the depletion of sodium and potassium.
Anatomical Factors Driving High Output
The location where the stoma is created is the primary determinant of baseline output consistency and volume. An ileostomy, which diverts output from the small intestine (ileum), carries the highest risk for high output because it bypasses the large intestine’s natural function. The colon is responsible for absorbing large volumes of water and electrolytes, often more than five liters per day, and without it, this fluid is lost through the stoma.
Following an ileostomy, the remaining small intestine begins a process called adaptation, increasing its efficiency in absorbing fluid and nutrients over several weeks to months. If this adaptation is inadequate, or if a significant length of the small intestine was removed during surgery, the patient may have persistently high output. This condition is known as Short Bowel Syndrome (SBS), which is typically defined by having less than 200 centimeters of small bowel remaining.
Patients with an ileostomy typically have a normal output of 600 to 1,200 milliliters per day, with the consistency of porridge or toothpaste. In contrast, a colostomy is formed from the large intestine and often retains enough colon to continue absorbing water. This results in thicker, lower-volume output, typically between 200 and 600 milliliters daily. Output significantly exceeding 1,500 milliliters per day is defined as a clinically concerning high-output stoma, regardless of the cause.
Dietary and Fluid Triggers
External factors related to consumption can dramatically influence the volume and watery nature of stoma output. Foods with a high content of simple sugars, such as fruit juices, sodas, honey, and hard candies, can draw excess water into the bowel through osmosis. This osmotic effect leads to a rapid increase in watery stoma discharge.
Certain types of fiber, particularly high amounts of insoluble fiber found in whole grains, raw vegetables, and nuts, can pass through the digestive tract undigested, increasing the bulk and watery nature of the output. High-fat foods, including fried foods and creamy sauces, can also increase stoma output by overstimulating the digestive tract. Spicy foods and alcohol are common irritants that hasten intestinal transit time, resulting in looser, higher-volume output.
The type of fluid consumed is important, as drinking plain water or hypotonic fluids (those with a low salt concentration, like tea or coffee) can worsen dehydration when output is high. These fluids pass quickly through the bowel and are not absorbed effectively, potentially driving the output and leading to a cycle of thirst and fluid loss. Consuming oral rehydration solutions (ORS) that contain a specific balance of glucose and sodium is preferred, as this combination is absorbed more efficiently by the remaining small intestine, helping to replenish lost fluids and electrolytes.
Medications and Infection
Chemical and biological agents can acutely trigger a high-output stoma by directly irritating the bowel lining or altering the gut environment. Many common prescription and over-the-counter medications are known to increase output and may need adjustment for ostomy patients. Antibiotics are a frequent culprit because they disrupt the natural balance of gut bacteria, which can lead to diarrhea.
Other medications, such as the diabetes drug metformin, have been documented to cause increased stoma output in some patients. Laxatives, which are designed to increase bowel motility, and certain magnesium-containing antacids or supplements can also result in significant fluid loss. In some cases, the sudden withdrawal of certain drugs, such as steroids or opiates, can cause a rebound increase in output.
Infections are a serious cause of acute, watery output due to inflammation and accelerated transit time in the bowel. Gastroenteritis from viruses or bacteria can affect anyone, but the risk and severity are heightened in ostomy patients. A particular concern is the bacterium Clostridioides difficile (C. diff), which can cause severe inflammation and life-threatening diarrhea, especially in those who have recently taken antibiotics. Any sudden, persistent increase in stoma output should be medically investigated to rule out an underlying infection.
Recognizing Danger Signs and Seeking Help
A sustained high output is a medical emergency due to the rapid fluid and electrolyte loss, which can lead to acute kidney injury. Monitor your output closely; a volume exceeding 1.5 to 2.0 liters in a 24-hour period is an indicator that you need medical attention. The consistency of the output becoming completely watery, resembling urine, is another red flag.
Warning signs of severe dehydration and electrolyte imbalance include persistent, intense thirst, dizziness, lightheadedness, and a dry mouth and tongue. Other serious symptoms include a rapid heart rate, muscle weakness or cramping, dark-colored or very low urine output, and confusion or unusual fatigue. If the high output is accompanied by a fever, persistent vomiting, or blood in the stoma output, contact your healthcare provider or emergency services immediately.