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Dehydration as a cause of constipation
Last reviewed: 04.07.2025

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Important information about water
Adults are made up of approximately 65% water, and a child up to 75%. Water is the source of life. Every day we lose about 4% of water, which needs to be replenished, especially during hot weather in countries with hot climates.
When a person's body temperature rises above 37°C, it is recommended to increase the volume of liquid by 250 ml for every degree above 37ºC. In addition, it is necessary to control the air temperature in the room - it should be moderate.
To prevent dehydration, you should know the standards that have been created on the basis of scientific research and have been taken into account based on the recommendations of the European Food Safety Authority (EFSA) Group on Dietetic Foods and Allergies. The organisms most vulnerable to dehydration are pregnant women, infants, children, the elderly and the disabled.
Why does dehydration cause constipation?
Because with insufficient water consumption, feces become dry and pass poorly through the intestines. Water is instantly absorbed by the intestinal walls, it does not get into the feces, so the intestines become difficult to pass. Hence constipation - with strong straining - minimal results.
Fluid intake for adults
For adults over 19 years of age, daily fluid intake is 2 liters per day for women and 2.5 liters for men. The same requirements apply to girls and boys aged 14 to 19 years. From the practice of combating constipation, it is known that fluid intake is a separate issue - its amount depends not only on environmental conditions, but also on diet and exercise.
Pregnant women are at increased risk of dehydration because they may have greater trouble getting enough water due to aversions to certain foods or reluctance to drink fluids due to morning sickness. They also often suffer from constipation.
During pregnancy, the need for water increases due to weight gain. The mother-to-be typically gains 10 to 15 kg, as well as increased energy demand, increased blood volume, amniotic fluid accumulation, and increased water excretion that may occur during morning sickness. Women expecting a baby should drink at least 2.3 liters of fluid daily, and those breastfeeding should drink even 2.7 liters per day.
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Children under special supervision
Infants and children are more susceptible to dehydration than adults. Recommendations for infant and child water intake include moderate temperatures and moderate physical activity. Infants and children need water to replenish the deficiencies of proper breathing, sweating, urination, and intensive development of the body. Diarrhea and vomiting, which are quite common in children, can lead to dehydration if the lack of water is not completed. Therefore, constipation is possible in young children due to dehydration.
Since children cannot communicate their needs clearly, and toddlers may be too preoccupied with what they are doing to forget to drink on time, the role of adults is very important to prevent them from becoming dehydrated, especially during the summer or when they are sick.
In hot weather, you can give children chilled drinks - those that they like. All drinks, including water, milk, juices, carbonated drinks and other liquids, irrigate the intestines and moisten the stool. Then there will be no problems with constipation. You should also protect children from overheating on hot days by offering them to rest in the shade.
Interestingly, choosing drinks for children helps them achieve better results in concentration tests and improves short-term memory, and also helps the learning process. Therefore, it is necessary to ensure that the body is properly hydrated even when children are at school. This will also save them from problems related to constipation.
Dehydration is especially dangerous in old age.
Dehydration can cause serious problems in old age, and can even be life-threatening. People aged 85-99 years are 6 times more likely to be hospitalized for dehydration than people aged 65-69 years.
Older people are at greater risk for a variety of reasons. Generally, you should drink when you feel thirsty. However, for people over 60, fluids may not be enough if they only drink when they feel thirsty. This is because an older person’s body is not as quick to signal its needs and it is time to show signs of dehydration, but still not thirsty.
The need to drink can also be blocked by taking certain medications. Consider the fact that many elderly people have memory problems. Therefore, doctors and relatives should remind elderly people to drink enough fluids by writing down on paper when and how the elderly person should drink water.
The kidneys' ability to concentrate urine usually decreases with age, leading to increased water excretion. In addition, problems with appetite or poor nutrition may lead to decreased fluid intake.
Chronic dehydration is a serious problem and is associated with an increased risk of falls, urinary tract infections, oral diseases, lung disease, kidney stones, constipation, and even cognitive impairment. Therefore, older adults should have easy access to fluids at all times of the day and night.
Pay attention to the heat!
In hot weather, it should be remembered that in addition to the usual loss of water, which can vary from 2 to 3 liters per day, not only these losses should be taken into account, but also the loss of mineral salts - especially sodium and potassium. Water covers 70 to 80% of a person's daily needs, the remaining 30% comes from food.
A rich source of fluid is berries, especially strawberries, melon, grapefruit, grapes, peaches, pears, oranges, apples. And also vegetables such as cucumbers, lettuce, celery, tomatoes, zucchini, broccoli, onions, carrots. They contain from 80 to 95% water. Maintaining a daily hydration balance, keep in mind that even rice, spaghetti and seafood contain from 65 to 80% water.
Most drinks are a source of vitamins, minerals and electrolytes, which are necessary for the normal functioning of the body and the prevention of constipation.
Symptoms of dehydration
Sometimes you ignore the first signs of dehydration, such as headaches, fatigue, thirst, which appears only in the middle of the dehydration phase. The next symptom is lethargy, loss of skin elasticity, rapid heartbeat. Severe dehydration is accompanied by a loss of 10% of body weight, as well as symptoms such as rapid breathing, cold clammy skin, changes in mental status - this is life-threatening and requires immediate medical attention.
Conversely, by drinking enough water, you eliminate these unpleasant problems from your life by having a healthy gut and eliminating all constipation problems.