An enema is a technique in which a solution is administered into a person's rectum to stimulate the release of large bowel movements and clean the large intestine. It is used to relieve persistent constipation or to clear the colon before various procedures, such as x-rays or other examinations. In some cases, an enema will be self-administered. In other cases, a physician or other medical professional will perform the procedure.

Enemas work by softening the feces and distending the colon and rectum. A combination of water and a mild soap or saline is often used in the solution. Enemas are also available in prepackaged solutions with various active ingredients. 

Before using an enema, patients should consult their physician. Conditions of concern regarding enemas include kidney disease, pregnancy and breastfeeding, and sodium-restricted diets. If the enema is to be self-administered, patients should check water temperature with a thermometer to ensure that it is not too hot.

Enemas can be taken using several positions. Most involve lying down or bending over and bending the knees. The tip of the enema bottle is inserted into the rectum and the solution is squeezed or allowed to flow inside.

Patients who experience a strong cramp after administering an enema should not stand up. This will add gravity to the force generated by the colon that is trying to expel the enema and fecal matter. Standing up at this point greatly increases the chances for an accident. Instead, patients should wait for 10 to 15 seconds while the pressure passes and then get up and sit on the toilet to evacuate their bowels.

An enema is a method of cleansing the large intestine in which a solution is injected into the rectum. This technique softens the feces and distends the colon and rectum, which causes the bowel to empty more easily.

Enemas are used to relieve persistent constipation. Some people consider them a means to cleanse the colon.  Enemas are either performed by the patient at home or in a hospital or office under the care of a medical professional.

Enemas are also used before some medical procedures. Patients who are preparing for imaging tests such as sigmoidoscopy or colonoscopy sometimes receive enemas to empty the colon before the tests. This improves the physician’s ability to view the area. A barium enema is another imaging test used to view the colon. An enema solution that includes barium is used, followed by x-rays that can show the outline of the colon and potential problems such as polyps. Enemas are sometimes administered to women before childbirth, although this practice has become less common.

Medications may also be administered via enema. For instance, patients with severe vomiting who cannot keep down oral medications may receive enemas. People with ulcerative colitis sometimes receive corticosteroid medications in enema form to reduce inflammation.

Enemas are administered using a solution, such as a combination of water and a mild soap or saline. They are also available in prepackaged solutions with active ingredients such as monobasic sodium phosphate, dibasic sodium phosphate, bisacodyl or mineral oil.  

Before using an enema, patients should consult their physician. Conditions of concern regarding enemas include kidney disease, pregnancy and breastfeeding, and sodium-restricted diets. Other conditions that may preclude use of enemas include:

• Congenital megacolon. Life-threatening complication of other intestinal conditions marked by symptoms such as inflated colon, abdominal distention and fever.
  
  
• History of bowel obstruction. Blockage or clogging of the intestines that prevents the passage of food.
  
  
• Imperforate anus. A birth defect that results in a lack of opening at the anus.
  
  
• History of congestive heart failure. Disorder in which the heart loses its ability to pump blood efficiently.

In addition, enema use is not generally recommended in children under the age of 2.

If the enema is to be self-administered, it is crucial that the patient create a solution that is not too hot. Water temperature should always be checked with a thermometer before the water is placed in the enema container. Most patients prefer warm water enemas, although there are instances where cooler water may be more effective at removing water and material stuck in the bowel.

Temperatures should be in the following range. Water should never be warmer than 113 degrees Fahrenheit (45 degrees Celsius), because this can scald the colon:

Physicians may also recommend that patients consume one or two glasses of water prior to taking the enema. This can help prevent dehydration which is sometimes caused by the procedure.

Enemas can be taken in several ways. Patients often use the Sims position, in which they lie on their left sides and flex their right leg, bringing their knee up to their chest. This allows the solution to flow more easily into the colon.

Some patients use the “knee-chest” position, in which the patient bends over so the chest is almost touching the ground. This leaves the abdomen almost upside down, allowing water to flow down from the rectum to the transverse colon. This position is most often used to clear severe stool impaction.

Another popular position is to lie on the back with knees raised and head propped against a wall.

Other variations of these positions include:

• Lying face down and arching the back. Helps keep the abdomen off the floor.
  
  
• Lying on the right side. The opposite of the Sims position, this allows the solution to flow into the right-sided colon.
  
  
• Reclining in a bathtub. Allows the patient to be unconcerned about any leakage.

The enema solution is kept in a plastic container that is attached to a long tube or nozzle. This nozzle tip may come prelubricated. If not, a water-based lubricant should be applied. The tip is then gently inserted 4 to 6 inches (6 to 15 centimeters) into the rectum. The solution is then slowly administered into the rectum. Patients should follow all instructions from the enema package or from a medical professional. Children may require dosage adjustments to prevent serious side effects. These adjustments are usually dependent on the child’s age and weight.

Patients may experience some discomfort, which can be partially alleviated by breathing deeply and slowly through the mouth. Some patients may experience cramps. If this occurs, administration of the solution should be slowed or stopped momentarily.

Once the solution has been administered, the patient will likely feel an immediate need to have a bowel movement. It is best to wait at least three minutes before defecating to achieve the best results. Most people find it difficult to hold an enema for more than five minutes.

Patients who experience a strong cramp should not stand up, as this will add gravity to the force generated by the colon that is trying to expel the enema and fecal matter. Standing up at this point greatly increases the chances for an accident. Instead, patients should wait for 10 to 15 seconds while the pressure passes, and then get up and sit on the toilet. Patients who experience intense pressure can keep the enema solution from leaking out by holding the buttocks together until the pressure passes. Patients can also reduce pressure by gently massaging the abdomen with both hands.

Most patients expel their enema while sitting on the toilet or using a bedpan in a hospital.

Patients should not sit on the toilet for more than a few minutes while waiting for the enema to be expelled. Straining to expel during a bowel movement is the chief cause of hemorrhoids. Patients who cannot expel their enema should return to their original position for a while before trying again to expel the contents.

Patients who undergo an enema under the supervision of a health care professional should not flush the toilet after completing their bowel movement, because it is important that a nurse or other medical professional examine the contents.

Some patients may experience side effects after administering an enema. These may include:

• Abdominal discomfort and cramping
• Feelings of faintness
• Burning in the rectum

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following enema-related questions:

1. Why are you recommending that I have an enema?
   
   
2. Will you administer my enema or will I?
   
   
3. Which tests will follow my enema?
   
   
4. How will an enema work to relieve my constipation?
   
   
5. What should be the temperature of the water used in my enema?
   
   
6. What is the best body position for administering my enema?
   
   
7. What side effects may I develop from enema use?
   
   
8. What should I do if I experience cramping during the enema and need to have a bowel movement?
   
   
9. Do I face any risks by undergoing an enema?
   
   
10. Will an enema adversely affect any other medical conditions I may have?