Staying Hydrated With an Ostomy

Most adults with a colostomy need around 1.5–2 litres of fluid per day, the same as the general population. Those with an ileostomy or urostomy typically need more — often 2–3 litres or above — because substantial fluid is lost through stoma output that the large bowel would normally reabsorb. Electrolyte balance matters as much as volume; plain water alone is sometimes insufficient. Always confirm personal targets with your stoma care nurse.

Why Ostomy Type Changes Everything

The part of the bowel or urinary tract that has been diverted determines how great a hydration challenge you face.

Colostomy

Because most of the colon remains intact, water reabsorption is relatively preserved. Output tends to be semi-formed, and fluid losses are close to those of the general population. Standard fluid intake guidance usually applies, though any illness causing vomiting or diarrhoea quickly raises the risk of dehydration.

Ileostomy

The large bowel is bypassed entirely, so the body loses the segment most responsible for reabsorbing water and electrolytes — particularly sodium. Ileostomy output is liquid to semi-liquid, and daily fluid losses can be substantial. A high-output ileostomy (typically defined as output exceeding 1,500 ml per day) dramatically increases the risk of dehydration, hyponatraemia (low sodium), and kidney complications over time.

Urostomy

A urostomy diverts urine directly through the abdominal wall, bypassing the bladder. Adequate hydration is critical both to prevent urinary tract infections and to reduce the risk of kidney stones, which form more readily when urine is concentrated. Clinicians often advise urostomy patients to aim for pale-yellow urine as a practical guide to adequate intake.

Recommended Fluid Intake

Specific targets vary between individuals depending on body size, climate, activity level, remaining bowel length, and underlying condition, so the figures below are general orientation only.

Ostomy type	Typical daily fluid guidance
Colostomy	~1.5–2 litres
Ileostomy	~2–3 litres or more
Urostomy	~2–2.5 litres or more

Your stoma care nurse or clinician will give you a personalised target. Do not attempt to self-prescribe specific fluid volumes, particularly if you have kidney, cardiac, or other conditions that require careful fluid management.

What to Drink

Not all fluids hydrate equally well for ostomates.

• Oral rehydration solutions (ORS): Clinically formulated to deliver the optimal ratio of sodium, glucose, and fluid for intestinal absorption. Particularly valuable for people with ileostomies or high-output stomas, where plain water can paradoxically increase output without improving net hydration.
• Water: The default choice for most people with a colostomy or urostomy. For ileostomy patients with high output, plain water should be complemented with sodium-containing fluids.
• Diluted fruit juice and squash, milk, and herbal teas: All contribute to daily intake. Milk also provides electrolytes.
• Alcohol and caffeinated drinks: Both have diuretic properties and can increase stoma output. They are not prohibited, but are best consumed in moderation and should not be the primary source of hydration.
• Carbonated drinks: May increase wind and bloating; individual tolerance varies.

Recognising Dehydration

Early and prompt recognition of dehydration is important because the condition can escalate quickly, particularly in ileostomy patients.

Early Signs

• Thirst and a dry mouth
• Darker-than-usual urine or reduced urine output
• Fatigue and light-headedness
• Headache
• A decrease in stoma output that suddenly follows a period of very high output (the body may be becoming depleted)

Signs Requiring Urgent Medical Attention

• Confusion or marked drowsiness
• Rapid heartbeat or low blood pressure
• Muscle cramps (a sign of electrolyte depletion)
• No urine output for several hours
• Persistent vomiting making fluid replacement impossible

If you experience severe or worsening symptoms, seek emergency medical care without delay.

Electrolytes: The Often-Overlooked Component

Fluid balance is inseparable from electrolyte balance. Sodium, in particular, is essential for the body to retain water effectively. People with ileostomies can lose significant sodium in their output; replacing fluid without sodium can worsen the imbalance. Oral rehydration solutions are specifically designed to address this. Adding a small amount of salt to food and choosing savoury fluids (such as diluted stock) can support sodium intake, but specific strategies should be discussed with your clinical team rather than self-prescribed.

Practical Daily Strategies

• Spread fluid intake throughout the day rather than drinking large volumes at once, which can increase stoma output rapidly.
• Monitor your stoma output — a sudden increase in volume or a very watery consistency is a signal to increase fluid and electrolyte intake and contact your stoma care nurse.
• Keep a small supply of ORS sachets at home, particularly if you have an ileostomy, for use during illness or hot weather.
• Check urine colour as a simple daily indicator: pale straw-yellow suggests adequate hydration; dark amber suggests you need more fluid.
• Inform your travel and activity plans — air travel, hot climates, and vigorous exercise all increase losses and require proactive adjustments.

When to Contact Your Stoma Care Nurse or Clinician

Contact your stoma care nurse promptly if:

• Your daily output has increased significantly for more than 24–48 hours
• You are unable to keep fluids down
• You notice early dehydration signs that do not resolve with increased fluid intake
• You are unwell with vomiting, diarrhoea, or fever

Regular review appointments are also an opportunity to reassess your fluid targets as your situation changes.

The Bottom Line

Staying well hydrated with an ostomy means matching your fluid and electrolyte intake to the type and output of your stoma — and recognising that individual needs differ considerably. Ileostomy and urostomy patients face the greatest challenge and generally require more fluid than the average person. Oral rehydration solutions play an important role when output is high. Monitor urine colour, know the early signs of dehydration, and keep your stoma care nurse informed of any significant changes. Always consult your stoma care nurse or clinician to establish a hydration plan tailored to your individual circumstances.