Nursing care
Ileostomy vs colostomy: why the output differs and what that changes for the nurse
Written and reviewed by Nicole Ramirez, BSN, RN, CMSRN · 4 min read · Updated November 2026
Short answer
An ileostomy brings the end of the small intestine (ileum) out to the skin, so output is liquid to pasty and fluid losses are high. A colostomy brings out part of the colon, so output thickens the farther along the colon the stoma sits. The ileostomy carries the bigger dehydration risk, because the colon that reclaims water has been bypassed.
The deciding finding: what comes out, and why
The colon reclaims water and electrolytes from intestinal contents. An ileostomy diverts stool before it reaches the colon, so MedlinePlus describes the output as thin or thick liquid or pasty, with most people emptying the pouch 5 to 8 times a day. The American Cancer Society notes it may stay watery for weeks after surgery before becoming more paste-like.
A colostomy diverts stool after part of the colon. MedlinePlus notes colostomy stool is often softer than normal, and the American Cancer Society describes more formed stool from descending and sigmoid colostomies. So the question of which ostomy has liquid stool has two answers: always the ileostomy, and sometimes a right-sided colostomy.
Why dehydration is mainly an ileostomy problem
Without the colon, an ileostomy loses fluid and electrolytes with every pouch emptying. The American Cancer Society warns of a greater risk of electrolyte imbalance and lists increased thirst, dry mouth, decreased urine output, lightheadedness and tiredness as dehydration signs. Teaching includes drinking 8 to 10 glasses of fluid a day, more in heat or exercise.
In hospital, high watery output needs the same attention. The nurse tracks intake and output closely, weighs the patient as ordered, and reports falling urine output or dizziness. Drinks that contain electrolytes, such as sports drinks, are often advised when output is loose, while a colostomy with formed stool rarely raises this concern.
Skin, blockage and irrigation
Liquid output reaches the skin easily, and the American Cancer Society notes that ostomy output can make peristomal skin sore. A barrier opening no more than 1/8 inch larger than the stoma limits that contact. The ileum is narrow, so food blockage is an ileostomy concern: cramping, a swollen stoma, nausea and sudden very watery output are warning signs, and MedlinePlus advises calling the provider if the pouch stays empty for 4 to 6 hours.
Can you irrigate an ileostomy? Not a standard end or loop ileostomy; the American Cancer Society does not describe routine irrigation for it. Irrigation, which works like an enema through the stoma, is an option some people with a descending or sigmoid colostomy choose to regulate emptying, after teaching from an ostomy nurse. An exam answer that irrigates an ileostomy is wrong.
Stoma checks and medication clues for both
A healthy stoma of either type is pink or red, moist and slightly shiny, according to MedlinePlus. Purple, black or white tissue suggests poor blood supply and needs reporting right away. Both types can be temporary while a bowel connection heals, or permanent, as the United Ostomy Associations of America describes.
Pouches are emptied when about one third to one half full, so they do not pull away from the skin. Whole tablets or capsules seen in the pouch should be reported, since the dose may not have been absorbed; the American Cancer Society links this to ascending and transverse colostomies, where transit is shorter.
Hypothetical practice scenario
Hypothetical scenario, not a real exam item: on day four after an ileostomy, a client has emptied the pouch eight times today with watery output, reports dizziness on standing, and has passed little urine this shift. Which action comes first: teach pouch emptying technique, check orthostatic vital signs and report, or suggest a low-fiber snack?
Checking orthostatic vital signs and reporting comes first, because the findings point to fluid volume deficit from high ileostomy output. Teaching technique feels natural, since new ostomates need it, but it ignores a client who may be getting dehydrated. Diet changes come later, under the team's plan.
Sources and further reading
MedlinePlus: Ileostomy - discharge. Liquid or pasty output, emptying 5 to 8 times daily at one third to one half full, fluid intake, blockage signs, empty pouch for 4 to 6 hours, healthy stoma color.
American Cancer Society: Ileostomy Care. Watery output after surgery, electrolyte imbalance and dehydration signs, narrow ileum and blockage, skin soreness, irrigation only for continent ileostomy catheters.
American Cancer Society: Colostomy Care. Irrigation for descending or sigmoid colostomies, barrier sizing, pills in the pouch with ascending or transverse colostomies.
MedlinePlus: Colostomy. Colostomy stool often softer than normal, temporary or permanent colostomies, pink moist stoma.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our gastrointestinal practice questions are the closest set to what this page covers.
Common questions
Which ostomy has liquid stool?
The ileostomy. Its output is liquid to pasty because the colon has been bypassed. A colostomy can also be loose if it sits in the ascending or transverse colon, while a descending or sigmoid colostomy usually gives more formed stool.
Why is dehydration a risk with an ileostomy?
The colon normally reclaims water and electrolytes. With an ileostomy that absorption is lost, so high output can quickly cause thirst, dry mouth, low urine output and lightheadedness. Teach generous fluid intake and when to call the provider.
Can you irrigate an ileostomy?
Not a standard ileostomy. Irrigation is an option some people with a descending or sigmoid colostomy use to regulate bowel emptying, taught by an ostomy nurse. A continent ileostomy is drained and flushed through a catheter, which is a different procedure.