Intestinal pseudo-obstruction (IPO) is a clinical syndrome caused by severe impairment in the ability of the intestines to push food through. It is characterized by the signs and symptoms of intestinal obstruction without any lesion in the intestinal lumen. Clinical features mimic those seen with mechanical intestinal obstructions and can include abdominal pain, nausea, abdominal distension, vomiting, dysphagia and constipation depending upon the part of the gastrointestinal tract involved.

It is a difficult condition to diagnose, requiring exclusion of any other mechanical cause of obstruction. Many patients are diagnosed late in the course of disease after additional symptoms are seen. Mortality is also difficult to accurately determine. One retrospective study estimated mortality to be between 10 and 25% for chronic intestinal pseudo-obstruction (CIPO) and to vary greatly depending on the etiology of the condition. When present for less than six months, it is diagnosed as acute IPO or Ogilvie syndrome. Longer than this is considered chronic. Owing to the difficulty of diagnosis, few studies are available which have attempted to estimate its prevalence.

The condition can begin at any age. Most studies describing CIPO are in pediatric populations. It can be a primary condition (idiopathic or inherited) or caused by another disease (secondary). It can be a result of myriad of etiologies including infectious, parasitic, autoimmune, genetic, congenital, neurologic, toxic, endocrinological, or anatomical pathology.

Treatment targets nutritional support, improving intestinal motility, and minimizing surgical intervention. Bacterial overgrowth of the small intestine can occur in chronic cases – presenting as malabsorption, diarrhea, and nutrient deficiencies – which may require the use of antibiotics.

Clinical features of IPO can include abdominal pain, nausea, abdominal distension, vomiting, dysphagia, and constipation. Symptoms depend on the portion of the gastrointestinal tract involved and the duration of symptoms. Symptoms may occur intermittently and over a prolonged period of time. It is not unusual for patients to present several times owing to the nonspecific nature of the symptoms. Conditions and onset will vary if the disease is primary vs secondary and the underlying disease (if a secondary manifestation) and its management.

Symptoms indicative of advanced disease and possible intestinal failure include diarrhea, loss of appetite, sepsis, bloating, fatigue, signs of low volume status, and malabsorption including nutritional deficiencies and foul-smelling stools.

According to a 2013 study conducted in Japan, the estimated prevalence of CIPO was between 0.80 and 1.00 per 100,000 people, while its incidence rate was reported as 0.21 to 0.24 per 100,000. Furthermore, some studies have indicated that CIPO is more prevalent in females, a trend that may be attributable to the higher rates of secondary CIPO from conditions more common in this demographic. In the case of pediatric intestinal pseudo-obstruction (PIPO), the incidence was estimated at approximately 1 per 40,000 live births.

In primary CIPO (the majority of chronic cases) the condition results from disruption of the intestine's ability to move food. These can be broadly classified as myopathic (affecting the smooth muscle), mesenchymopathic (affecting the interstitial cells of Cajal), or neuropathic (of the nervous system) of the gastrointestinal tract.