What is an enema?

An enema is a therapeutic procedure that involves inserting a rectal tube or duckbill tube into the colon through the anus to infuse liquids for the purpose of relieving constipation or expelling gas.

What conditions can enemas treat?

• Severe constipation: If a patient has not had a bowel movement for more than three days, experiences difficulty defecating, or feels dry, hard stool accumulated in the rectal cavity that is hard to pass, with a sensation of rectal fullness, an enema may be used to assist bowel movements.
• Intestinal obstruction: In most cases, patients with intestinal obstruction may consider an enema, as it can partially relieve intestinal blockage, promote the excretion of intestinal contents, and alleviate symptoms.
• Colitis: Enemas are also an important treatment method for colitis. Typically, medication is delivered directly to the affected area through the anus, which can reduce the adverse effects of systemic medication.

What other situations require an enema?

• High fever: For patients with high fever, administering a low-temperature solution via the intestines can help rapidly lower body temperature.
• Before a colonoscopy: Since stool can obstruct the doctor's view of the intestines, an enema is performed before a colonoscopy to empty the bowels.
• Before surgery: Preoperative enemas can reduce intestinal gas during surgery, avoiding adverse effects on the procedure.

What are the different types of enemas?

There are several types of enemas, with the most common being large-volume non-retention enemas, small-volume non-retention enemas, and retention enemas.

• Large-volume non-retention enema: A certain amount of liquid is infused into the colon through the rectum to soften stool, clear fecal matter and gas from the intestinal cavity, and lower body temperature. It is suitable for patients with stubborn constipation, high fever, heatstroke, or as preparation for surgery or examinations.
• Small-volume non-retention enema: A small amount of liquid is infused into the intestines to soften stool and relieve constipation. It is suitable for post-abdominal surgery patients, critically ill patients, the elderly, those with weakened constitutions, children, and those who cannot tolerate large-volume non-retention enemas.
• Retention enema: Medication is infused through the anus and retained in the rectum or colon, where it is absorbed through the intestinal mucosa to treat intestinal diseases. It can also be used for sedation or sleep induction.

What precautions should be taken with enemas?

• Before an enema, the patient should rest quietly, avoid tension, relax the body, and maintain a side-lying position with the anus exposed.
• For non-retention enemas, the enema solution should generally be retained for 5–10 minutes before being expelled along with stool. However, if the enema is used to reduce fever, the solution should be retained for about 30 minutes.
• For retention enemas, the retention time should follow the doctor's instructions, usually exceeding 1 hour.

What effects can enemas have on the body?

• Intestinal perforation: Long-term enemas can cause mechanical damage to the intestinal mucosa, leading to perforation, which can be life-threatening if not treated promptly.
• Impaired natural bowel movements: Frequent enemas may disrupt the balance of intestinal flora, causing diarrhea, bloating, or constipation. Patients may become dependent on enemas, creating a vicious cycle.

What are the contraindications for enemas?

• Generally, non-retention enemas are not suitable for patients with unexplained acute abdominal pain, gastrointestinal bleeding, or pregnant women.

1. For patients with unexplained acute abdominal pain, enemas may worsen abdominal symptoms.
2. For patients with gastrointestinal bleeding, enemas may exacerbate bleeding.
3. For pregnant women, enemas may stimulate uterine contractions, leading to premature birth or miscarriage. However, for women before delivery, appropriate enemas can cleanse the bowels and assist childbirth.
4. Additionally, large-volume non-retention enemas are contraindicated for patients with severe cardiovascular diseases, the elderly, those with weakened constitutions, or post-abdominal surgery patients, as infusing a large volume of liquid at once can burden the heart and gastrointestinal tract, affecting heart function or postoperative recovery.

• Retention enemas have a broader range of applications, and currently, there are no clearly defined contraindicated groups.