Sodium Phosphate Rectal

Reviewed on 2/2/2022

What Is Sodium Phosphate Rectal and How Does It Work?

Sodium Phosphate Rectal is a prescription medication used to treat constipation and for cleansing bowel.  

  • Sodium Phosphate Rectal is available under the following different brand names: Fleet Enema, Pedia-Lax Enema, Fleet Enema Extra


What Are Dosages of Sodium Phosphate Rectal?

Adult and pediatric dosage


  • (19g/7g)/118mL
  • (19g/7g)/197mL

Constipation & Bowel Cleansing

Adult dosage

  • 1 bottle rectally; not to exceed 1 administration/24 hours

Pediatric dosage

  • Children younger than 2 years of age: Do not use.
  • Children 2-4 years of age: Administer one-half bottle rectally of pediatric enema (ie, ~30 mL)
  • Children 5-11 years of age: Administer 1 bottle rectally of pediatric enema (ie, 59 mL)
  • Children 12 or older: Administer as in adults 

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."

What Are Side Effects Associated with Using Sodium Phosphate Rectal?

Common side effects of Sodium Phosphate Rectal include:

  • mild abdominal discomfort or cramps, and
  • gas

Serious side effects of Sodium Phosphate Rectal include:

  • hives, 
  • difficulty breathing, 
  • swelling of the face, lips, tongue, or throat, 
  • unusual dry mouth
  • increased thirst, 
  • lack of tears, 
  • dizziness, 
  • lightheadedness
  • pale or wrinkled skin, 
  • change in the amount of urine, 
  • severe or persistent stomach pain, 
  • bloody, tarry or black stools, 
  • rectal bleeding
  • mental or mood changes, 
  • confusion, 
  • unusual drowsiness, 
  • muscle weakness or spasms,
  • persistent diarrhea, 
  • swelling of the ankles, hands, or feet, 
  • slow, irregular, or fast heartbeat, 
  • seizures, 
  • rash, 
  • itching, and
  • severe dizziness

Rare side effects of Sodium Phosphate Rectal include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.


You are constipated if you don't have a bowel movement every day. See Answer

What Other Drugs Interact with Sodium Phosphate Rectal?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

  • Sodium Phosphate Rectal has severe interactions with the following drug:
  • Sodium Phosphate Rectal has serious interactions with the following drugs:
  • Sodium Phosphate Rectal has moderate interactions with the following drugs:
  • Sodium Phosphate Rectal has minor interactions with no other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this drug, tell your doctor or pharmacist of all the drugs you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Sodium Phosphate Rectal?


Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Sodium Phosphate Rectal?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Sodium Phosphate Rectal?”


  • Do not use laxatives when nausea, vomiting, or severe abdominal pain is present
  • Caution with renal impairment or ascites; increases risk of sodium retention and edema; obtain baseline and postprocedure labs in patients with renal impairment; monitor closely to avoid hyperphosphatemia
  • Caution in patients with a colostomy
  • Caution in children aged 2-11 years or elderly patients with comorbidities
  • Caution with pre-existing electrolyte disturbances or patients taking diuretics or other medications that may alter electrolytes
  • Additional liquids by mouth are recommended to prevent dehydration; inadequate fluid intake may result in hypovolemia due to excessive fluid loss
  • Exceeding daily dose, no return of enema solution, retention time over 10 minutes, or failure to have a bowel movement within 30 minutes of enema use may lead to electrolyte disturbances, including hypernatremia, hyperphosphatemia, hypocalcemia, and hypokalemia
  • Severe dehydration and electrolyte abnormalities associated with serious complications (eg, acute kidney injury, arrhythmias, and death) have occurred in adults and children who overdosed using oral or rectal over-the-counter (OTC) sodium phosphate solutions to treat constipation
  • Use caution in unstable angina, cardiomyopathy, history of myocardial infarction arrhythmia, patients with or at risk for arrhythmias, including prolonged QT interval, cardiomyopathy, recent myocardial infarction; caution with other QT-prolonging drugs, consider pre-/postdose ECGs and lab tests in high-risk patients
  • Correct dehydration prior to using in bowel preparations
  • Use caution in patients with gastric retention or hypomotility, severe active ulcerative colitis or ileus, severe, chronic constipation
  • Use caution in history of seizures, those at high risk of seizures or on seizure therapy; obtain baseline and postprocedure labs in high-risk patients
  • Phosphate absorption may increase in patients with chronic inflammatory bowel disease; phosphate may induce colonic aphthous ulceration; consider this when interpreting colonoscopic findings in patients with inflammatory bowel disease
  • Use caution in debilitated patients, including elderly patients; evaluate patients ability to hydrate properly if receiving bowel preparation
  • Purgatives and laxatives can be potentially abused by bulimia nervosa patients
  • Use caution in patients with impaired gag reflex and those prone to aspiration or regurgitation
  • When used for bowel evacuation, medications may not be well absorbed due to intestinal peristalsis
  • Exceeding recommended doses of OTC sodium phosphate preparation to treat constipation may potentially result in serious adverse effects; renal/cardiac adverse effects reported following severe dehydration and alterations in serum electrolytes, including sodium phosphate and calcium

Pregnancy and Lactation

  • Use with caution if benefits outweigh risks. Animal studies show risk and human studies are not available or neither animal nor human studies done.
  • Lactation: Unknown whether distributed in breast milk; caution because of risk for electrolyte disturbances or dehydration.  
  • Pregnant or breastfeeding patients should seek advice from a health professional before using OTC drugs.
Medscape. Sodium Phosphate Rectal.

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