Intestinal pseudo-obstruction

Intestinal pseudo-obstruction (IPO) is a clinical syndrome caused by severe impairment in the ability of the

It is a difficult condition to diagnose, requiring exclusion of any other mechanical cause of obstruction.[4] 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.^[5] When present for less than six months, it is diagnosed as acute IPO^[6] or Ogilvie syndrome.^[4] Longer than this is considered chronic.^[7] Owing to the difficulty of diagnosis, few studies are available which have attempted to estimate its prevalence.^[8]

The condition can begin at any age. Most studies describing CIPO are in

Treatment targets nutritional support, improving intestinal motility, and minimizing surgical intervention.[4] Bacterial overgrowth of the small intestine can occur in chronic cases – presenting as malabsorption, diarrhea, and nutrient deficiencies^[12] – which may require the use of antibiotics.

Presentation

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^[2] 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.^[4] 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

In some cases there appears to be a genetic association.[16] One form has been associated with DXYS154, some associated with defective ACTG2 gene^[17]

Secondary chronic intestinal pseudo-obstruction can occur as a consequence of a number of other conditions including:

• Hirschsprung's disease^[18] – the absence of colonic nerve cells
• Chagas' disease
   – a chronic parasitic infection of the colon leading to loss of nerve endings
• Kawasaki disease^[19][20] - a rare presentation for this particular autoimmune disorder of the vasculature
• Parkinson's disease^[21] - related to the neurodegeneration of gastrointestinal tract
• Autoimmune conditions — conditions including systemic lupus erythematosus and scleroderma lead to
  collagen vascular deposition^[22]
  and gastrointestinal motility disruption
• Mitochondrial disease^[23] - IPO is a known presentation for mitochondrial disease
• Endocrine disorders^[4]
• Certain medications.[15]

The term may be used synonymously with enteric neuropathy if a neurological cause is suspected.

Diagnosis

The symptoms of IPO are nonspecific. It is not unusual for patients to present repeatedly and to undergo numerous tests.^[4] Mechanical causes of intestinal obstruction must be excluded to reach a diagnosis of pseudo-obstruction. Attempts must also be made to determine whether the IPO is the result of a primary or secondary condition.^[15] A diagnostic work-up may include:^[14]

• Gastric motility studies
• Imaging studies:

  • 

    X-rays – may show intestinal air fluid levels (seen with true mechanical intestinal obstruction)
  • CT scans
  • Barium enema
• Blood tests
• Upper and lower endoscopies
• Manometry – used to measure pressure of esophagus and stomach

Classification

Pseudo-obstruction syndromes are classified as acute or chronic based on their clinical appearance. Acute colonic pseudo-obstruction (ACPO; sometimes known as Ogilvie syndrome) causes the colon to become grossly dilated; if not decompressed, the individual risks perforation, peritonitis, and death. Chronic intestinal pseudo-obstruction is a chronic disorder.^[24]

Treatment

Treatment for IPO (acute or chronic) is aimed at removing the disease process and/or managing the complications present. Focus is placed on management of pain, gastrointestinal symptoms, nutritional deficiencies, fluid status, infection control, and improving quality of life. When CIPO is secondary to another disease, treatment is addressed towards the underlying condition. Surgery is sometimes required in severe cases of CIPO.

Medical treatment

Prucalopride,^[25][26] pyridostigmine,^[11] metoclopramide, cisapride, erythromycin,^[9] and octreotide^[9][27][28] are medications that aim to enhance intestinal motility.

Intestinal stasis, which may lead to bacterial overgrowth and subsequently, diarrhea or malabsorption, is treated with antibiotics.

Colostomy or ileostomy can bypass affected parts if they are distal to (come after) the stoma. For instance, if only the colon is affected, an ileostomy may be helpful. Either of these ostomies are typically placed at or a few centimeters below the patient's navel per doctor recommendation based on the affected area of the intestines as well as concerns for patient comfort and future physical growth for children.[29]

The total removal of the colon, called a colectomy or resection of affected parts of the colon may be needed if part of the gut dies (for instance toxic megacolon), or if there is a localized area of dysmotility.

Gastric and colonic pacemakers have been tried. These are strips placed along the colon or stomach which create an electric discharge intended to cause the muscle to contract in a controlled manner.

A potential solution, albeit radical, is intestinal transplantation. This is only appropriate in the case of intestinal failure. These procedures are most frequently described in pediatric cases of CIPO.^[30][31] One operation involving multi-organ transplant of the pancreas, stomach, duodenum, small intestine, and liver, and was performed by Doctor Kareem Abu-Elmagd on Gretchen Miller.^[32]

Potential treatments

Further research is necessary into other treatments which may alleviate symptoms. These include

• Ogilvie syndrome: acute pseudoobstruction of the colon in severely ill debilitated patients.
• autonomic ganglia
  .
• Intestinal neuronal dysplasia: a disease of motor neurons leading to the bowels.
• Bowel obstruction: mechanical or functional obstruction of the bowel, most commonly due to adhesions, hernias or neoplasms.
• Enteric neuropathy: alternative name sometimes used for diagnosis in UK

References