Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that affects the large intestine, or colon. Inflammation in the lining of the colon causes belly pain and an urge to go to the bathroom. Frequent, watery bowel movements and abdominal pain are a common symptom of UC

Dehydration happens when you lose more fluid than you put into your body by drinking water. Frequent diarrhea from UC can reduce your body’s fluids to the point where you become dehydrated.

You can fix mild dehydration by drinking extra water. If you don’t get enough to drink and diarrhea continues, dehydration can become serious enough to damage your kidneys. It could even be life threatening.

Yes, UC inflames the lining of your intestine and prevents it from absorbing fluid. The extra water exits your body in watery bowel movements. People with severe UC can have six or more bowel movements a day.

Not everyone with UC becomes dehydrated. You’re more likely to get low on fluids if you:

  • aren’t able to drink enough water to compensate for what you lose
  • drink coffee or alcohol, which cause your body to remove extra fluid
  • sweat a lot from exercise or heat
  • had your colon removed or have an ileostomy

It’s important to drink water when you have UC. Having enough fluids will replenish what you lose through diarrhea.

Water alone may not be enough. Your body also loses electrolytes like salt, potassium, and magnesium when you have diarrhea.

Drinking water plus electrolytes can help you stay hydrated. You can find that combination in the form of an oral rehydration solution at your local pharmacy. Sports drinks such as Gatorade and Powerade also contain electrolytes and fluid.

The easiest way to stay hydrated is to drink plenty of water. Don’t wait until you feel thirsty.

Everyone’s fluid needs are different, but try to have about eight, 8-ounce glasses of water a day. You’ll know that you’re hydrated when your urine is light yellow in color.

If you’re concerned that drinking extra water will make your diarrhea worse, don’t worry. Water shouldn’t affect how often you need to go.

It’s especially important to drink enough water when you know you’ll lose extra fluids from sweating or when your diarrhea is flaring up. Bring a water bottle with you when it’s hot outside or you’re exercising, and keep drinking.

Remember that water isn’t the only way to stay hydrated. If you’re bored with the taste of water, add in other fluid sources, such as:

  • fruit juice
  • clear broth
  • ice pops
  • low-fiber fruits such as melon

Limit or avoid alcohol and diuretics such as coffee, tea, and soda. They’ll not only make you lose more fluid and get dehydrated faster, but they can worsen UC symptoms. The carbonation in soda can also cause uncomfortable gas.

Thirst is one of the main signs that you’re low on fluids. By the time you start to feel thirsty, you’re already dehydrated.

Other signs of dehydration are:

  • dry mouth
  • headache
  • going to the bathroom less often or passing only small amounts of urine
  • dark urine
  • lack of energy
  • tiredness

See a doctor if you have these signs of more severe dehydration:

  • dizziness
  • muscle cramps
  • pale skin
  • sunken eyes
  • confusion
  • fast breathing
  • rapid pulse

For mild to moderate dehydration, drinking an oral rehydration solution or sports drink should be enough to rehydrate you. Call your doctor if you’re not sure what to do.

Seek medical attention if you show signs of severe dehydration. You may need rehydration and other treatments in a hospital.

Diarrhea is one of the main symptoms of UC. You can lose fluids with every watery bowel movement, which could lead to dehydration.

Talk with your doctor about treatments to manage diarrhea so you don’t get dehydrated. Drink plenty of fluids each day. If you do become dehydrated, try an oral rehydration solution or sports drink to replenish fluids and electrolytes.