Ileus

Ileus is a disruption of the normal propulsive gastrointestinal motor activity from non-mechanical mechanisms. Motility disorders that result from structural abnormalities are termed mechanical bowel obstruction. Some mechanical obstructions are misnomers, such as gallstone ileus and meconium ileus, and are not true examples of ileus by the classic definition.

Types

Postoperative Ileus

It is a temporary paralysis of a portion of the intestines typically after an abdominal surgery. Since the intestinal content of this portion is unable to move forward, food or drink should be avoided until peristaltic sound is heard from auscultation of the area where this portion lies.

Acute colonic pseudoobstruction (Ogilvie's syndrome)

Pathogenesis

Inhibitory neural reflexes

Inflammation

Ileus may increase adhesion formation, because intestinal segments have more prolonged contact, allowing fibrous adhesions to form, and intestinal distention causes serosal injury and ischemia. Intestinal distention has been shown to cause adhesions in foals. In a recent survey of ACVS diplomates on drugs to prevent ileus and therefore prevent adhesions (unpublished data). The drug used in this survey was lidocaine, erythromycin, and cisapride. Some respondents also mentioned the importance of walking horses postoperatively to stimulate motility. Repeat celiotomy to decompress chronically distended small intestine and remove fibrinous adhesions is also a useful method of treating ileus and reducting adhesions, and it has been associated with a good outcome.

Neurohumoral peptides

Symptoms

Symptoms of ileus include, but are not limited to:

• moderate, diffuse abdominal discomfort
• 
  
constipation
• 
  
abdominal distension
• nausea/vomiting, especially after meals
• lack of bowel movement and/or flatulence
• excessive belching

Risk Factors

• gastrointestinal surgery or other GI procedures
• 
  
electrolyte imbalance
• 
  
hypothyroidism
• medications (e.g. opiates)
• severe illness

Treatment

Nil per os (NPO or "Nothing by Mouth") is mandatory in all cases. Nasogastric suction and parenteral feeds may be required until passage is restored.

There are several options in the case of paralytic ileus. Most treatment is supportive. If caused by medication, the offending agent is discontinued or reduced. Bowel movements may be stimulated by prescribing lactulose, erythromycin or in severe cases, (Ogilvie's syndrome) neostigmine.

If possible the underlying cause is corrected(e.g. replace electrolytes).