Idiopathic intestinal pseudo-obstruction is a disease of the muscular layer or of the enteric nervous system of the intestine. The myogenic form of idiopathic intestinal pseudo-obstruction is an autosomal dominant disease characterized by thinning of the intestinal musculature due to degeneration, fibrosis, malaligned smooth fibers and abnormal contractile filaments. All parts of the intestinal tract may be involved, but usually the small intestine, esophagus and colon are the most severely affected.

The neurogenic form of this disease is characterized by abnormal neuronal and glial cells. The damage may be in the spinal cord or in the splanchnic ganglia. When the splanchnic ganglia are involved, intranuclear inclusion bodies can be identified. The condition is characterized by abnormal systemic neural function, with an inappropriate blood pressure response to phenylephrine, Valsalva's maneuver, or achieving the upright posture. There is a lack of sweating on warming of the skin, pupillary denervation hypersensitivity, and lack of intestinal spike activity after small intestinal distention.

Treatment of both the myogenic and neurogenic forms of idiopathic intestinal pseudo-obstruction is generally unsuccessful. Various promotility agents have been tried with only transient success. The somatostatin analogue octreotide may be useful in some patients. Associated bacterial overgrowth may worsen bloating and diarrhea, and should be treated with antibiotics. Surgery only aggravates the disorder and provides long intervals of severe ileus. Home parenteral nutrition may be the only alternative to maintain the patient's nutritional status, reduce the frequency and severity of the associated intestinal complaints, and improve the quality of the patient's life.