Enema

An **enema**, also known as a **clyster**, is an injection of fluid into the lower bowel by way of the rectum. Also, the word **enema** can refer to the liquid so injected, as well as to a device for administering such an injection.

In standard medicine, the most frequent uses of enemas are to relieve constipation and for bowel cleansing before a medical examination or procedure; also, they are employed as a lower gastrointestinal series (also called a barium enema), to check diarrhea, as a vehicle for the administration of food, water or medicine, as a stimulant to the general system, as a local application and, more rarely, as a means of reducing temperature, as treatment for encopresis, and as a form of rehydration therapy (proctoclysis) in patients for whom intravenous therapy is not applicable.

## Acute treatments

As bowel stimulants, enemas are employed for the same purposes as orally administered laxatives: To relieve constipation; To treat fecal impaction; To empty the colon prior to a medical procedure such as a colonoscopy. A large volume of enema can be given to cleanse as much of the colon as possible of feces. However, a low enema is generally useful only for stool in the rectum, not in the intestinal tract.

Such enemas' mechanism consists of the volume of the liquid causing rapid expansion of the intestinal tract in conjunction with, in the case of certain solutions, irritation of the intestinal mucosa which stimulates peristalsis and lubricates the stool to encourge a bowel movement. In order for the enema to be the effective the patient should retain the solution for five to ten minutes, as tolerated. or, as some nursing textbooks recommend, for five to fifteen minutes or as long as possible.

### Large volume enemas

#### Water-based solutions

Plain water can be used, simply functioning mechanically to expand the colon, thus prompting evacuation.

Castile soap is commonly added because its irritation of the colon's lining increases the urgency to defecate. However, liquid handsoaps and detergents should not be used.

Glycerol is a specific bowel mucosa irritant serving to induce peristalsis via a hyperosmotic effect. It is used in a dilute solution, e.g., 5%.

Normal saline is least irritating to the colon, at the opposite end of the spectrum. Like plain water, it simply functions mechanically to expand the colon, but having a neutral concentration gradient, it neither draws electrolytes from the body, as happens with plain water, nor draws water into the colon, as occurs with phosphates. Thus, a salt water solution can be used when a longer period of retention is desired, such as to soften an fecal impaction.

#### Other solutions

Equal parts of milk and molasses heated together to slightly above normal body temperature have been used. Neither the milk sugars and proteins nor the molasses are absorbed in the lower intestine, thus keeping the water from the enema in the intestine. Studies have shown that milk and molasses enemas have a low complication rate when used in the emergency department and are safe and effective with minimal side effects.

Mineral oil functions as a lubricant and stool softener, but may have side effects including rectal skin irritation and leakage of oil which can soil undergarments for up to 24 hours.

### Micro-enemas

#### Single substance solutions

*In alphabetical order*

Arachis oil (peanut oil) enema is useful for softening stools which are impacted higher than the rectum.

Bisacodyl stimulates enteric nerves to cause colonic contractions.

Dantron is a stimulant drug and stool softener used alone or in combinations in enemas. Considered to be a carcinogen its use is limited, e.g., restricted in the UK to patients who already have a diagnosis of terminal cancer and not used at all in the USA.

Docusate

Glycerol has a hyperosmotic effect and can be used as a small-volume (2–10 ml) enema (or suppository).

Mineral oil is used as a lubricant because most of the ingested material is excreted in the stool rather than being absorbed by the body.

Sodium phosphate. Also known by the brand name Fleet. Available at drugstores; usually self-administered. Buffered sodium phosphate solution draws additional water from the bloodstream into the colon to increase the effectiveness of the enema. But it can be rather irritating to the colon, causing intense cramping or "griping." Fleet enemas usually causes a bowel movement in 1 to 5 minutes. Known adverse effects.

Sorbitol pulls water into the large intestines causing distention, thereby stimulating the normal forward movement of the bowels. Sorbitol is found in some dried fruits and may contribute to the laxative effects of prunes. and is available for taking orally as a laxative. As an enema for constipation, the recommended adult dose is 120 mL of 25-30% solution, administered once. Note that Sorbitol is an ingredient of the MICROLAX Enema.

#### Compounded from multiple ingredients

*In alphabetical order of the original brand names*

Klyx contains docusate sodium 1 mg/mL and sorbitol solution (70%) (crystallising) 357 mg/mL and is used for faecal impaction or constipation or for colon evacuation prior medical procedures, developed by Ferring B.V..

Micralax (not to be confused with MICROLAX®)

MICROLAX® (not to be confused with Micralax) combines the action of sodium citrate, a peptidising agent which can displace bound water present in the faeces, with sodium alkyl sulphoacetate, a wetting agent, and with glycerol, an anal mucosa irritant and hyperosmotic. However, also sold under the name "Micralax", is a preparation containing sorbitol rather than glycerol; which was initially tested in preparation for sigmoidoscopy.

Micolette Micro-enema® contains 45 mg sodium lauryl sulphoacetate, 450 mg per 5 ml sodium citrate BP, and 625 mg glycerol BP and is a small volume stimulant enema suitable where large-volume enemas are contra-indicated.

## Chronic treatments

### Transanal irrigation

Main articles: Transanal irrigation
*TAI*, also termed *retrograde irrigation*, is designed to assist evacuation using a water enema as a treatment for persons with bowel dysfunction, including fecal incontinence or constipation, especially obstructed defecation. By regularly emptying the bowel using transanal irrigation, controlled bowel function is often re-established to a high degree, thus enabling development of a consistent bowel routine. Its effectiveness varies considerably, some individuals experiencing complete control of incontinence but others reporting little or no benefit.

An international consensus on when and how to use transanal irrigation for people with bowel problems was published in 2013, offering practitioners a clear, comprehensive and simple guide to practice for the emerging therapeutic area of transanal irrigation.

The term *retrograde irrigation* distinguishes this procedure from the Malone antegrade continence enema, where irrigation fluid is introduced into the colon proximal to the anus via a surgically created irrigation port.

### Bowel management

Main articles: Bowel management
Patients who have a bowel disability, a medical condition which impairs control of defecation, e.g., fecal incontinence or constipation, can use bowel management techniques to choose a predictable time and place to evacuate. Without bowel management, such persons might either suffer from the feeling of not getting relief, or they might soil themselves.

While simple techniques might include a controlled diet and establishing a toilet routine, a daily enema can be taken to empty the colon, thus preventing unwanted and uncontrolled bowel movements that day.

## Adverse effects

Improper administration of an enema can cause electrolyte imbalance (with repeated enemas) or ruptures to the bowel or rectal tissues resulting in internal bleeding. However, these occurrences are rare in healthy, sober adults. Internal bleeding or rupture may leave the individual exposed to infections from intestinal bacteria. Blood resulting from tears in the colon may not always be visible, but can be distinguished if the feces are unusually dark or have a red hue. If intestinal rupture is suspected, medical assistance should be obtained immediately. Frequent use of enemas can cause laxative dependency.

The enema tube and solution may stimulate the vagus nerve, which may trigger an arrhythmia such as bradycardia.

Enemas should not be used if there is an undiagnosed abdominal pain since the peristalsis of the bowel can cause an inflamed appendix to rupture.

There are arguments both for and against colonic irrigation in people with diverticulitis, ulcerative colitis, Crohn's disease, severe or internal hemorrhoids or tumors in the rectum or colon, and its usage is not recommended soon after bowel surgery (unless directed by one's health care provider). Regular treatments should be avoided by people with heart disease or kidney failure. Colonics are inappropriate for people with bowel, rectal or anal pathologies where the pathology contributes to the risk of bowel perforation.

Recent research has shown that ozone water, which is sometimes used in enemas, can immediately cause microscopic colitis.

A recent case series of 11 patients with five deaths illustrated the danger of phosphate enemas in high-risk patients.