Chronic intestinal pseudo-obstruction

Abstract

Chronic intestinal pseudo-obstruction (CIP) is one of the four major categories into which diseases causing chronic benign intestinal failure can be classfied. 1 Patients with CIP constitute about 5% of those on home parenteral nutrition (HPN) in France, the UK and the USA. 2-5 In the Italian HPN register, 6 patients with intestinal obstruction represent about 12% of the total, but no distinction is made between organic obstruction and CIP. There are fewer data on home enteral nutrition (HEN). In a survey of 3708 HEN patients, Howard reported that 3.5% had motility disorders. 7 Comparable data from the Italian HEN register 8 indicate that motility disorders accounted for 1.5% of 829 patients with benign disease. CIP is caused by the failure of the intestine to propel its contents. This leads to signs and symptoms of bowel obstruction in the absence of a demonstrable occluding lesion. 9,1° The disordered propulsion may be due to dysfunction of either the smooth muscle or the enteric nerves or both. Primary or idiopathic CIP, is a heterogeneous group of diseases in which a primary alteration of smooth muscle or the myoenteric plexus has been demonstrated. Some of these diseases are familial, others are sporadic (familial visceral myopathy, familial visceral neuropathy, achalasia, Hirsprung's hypertrophic pyloric stenosis). CIP can also be secondary to a number of other circumstances. These include systemic diseases which involve smooth muscle (connective tissue diseases, mainly scleroderma, muscular dystrophies, amyloidosis, ceroidosis); neurological disorders (primary autonomic dysfunction, multiple sclerosis, Parkinson's disease, diabetic polyneuropathy, Chagas' disease); endocrine and metabolic disorders (hypothyroidism, hypoparathyroidism, uraemia, acute intermittent porphyria); drugs (opiates, anticholinergic agents, chemotherapy, anti-depressants, tranquillisers, antiParkinsonian, anthraquinones) and a variety of unclassifiable causes (post-operative pseudo-obstruction, jejunoileal bypass, organ transplant, paraneoplastic and radiation injury). When considering both primary and secondary CIP, more cases arise from visceral myopathies than from visceral neuropathy. T]he myopathy which accompanies scleroderma is the most frequent. CIP in children affects both sexes equally, whereas in adults a female:male ratio of 2:1 has been reported. The clinical manifestations of CIP depend on the site and extent of gastrointestinal tract involved and the cause and severity of the abnormal motility. Abdominal pain, distension and vomiting are the main clinical features. Involvement of the oesophagus may produce dysphagia, regurgitation and chest pain. Localisation to the stomach causes gastroparesis with epigastric bloating and pain, nausea and vomiting. Small intestinal involvement often causes bacterial overgrowth and the stagnant loop syndrome, which may lead to diarrhoea and steatorrhoea. Localisation to the colon leads to constipation. Signs and symptoms of malnutrition as consequence of reduced intake, malabsorption or intraluminal consumption of nutrients may also contribute to the clinical features. Diagnosis of CIP relies on techniques such as radiography, scintigraphy and tracer studies for gastrointestinal transit evaluation, and manometry and histopathology. Treatment of C1P involves drugs which act on gastrointestinal motility, antibiotics for bacterial overgrowth, surgery directed at specific problems, and home artificial nutrition. None of the treatments are curative or halt any of the disorders that cause CIP, except for some types of CIP which are secondary to systemic disease. For example, thyroid disease responds favourably to treatment, but scleroderma and diabetic enteropathy do not. Patients with extensive involvement of the small intestine have the most severe features of CIP and are those who may require HPN. In these patients the prokinetic agents metoclopramide and domperidone appear to be ineffective. The uncontrolled use of cisapride in 106 patients improved the symptoms in most of them, 11 however, in another study, although it decreased intestinal transit time in patients with CIP, a controlled trial of long-term therapy did not confirm its usefulness. 12 Erythromycin induces the migrating motor complex and has been used in a few patients, but its efficacy