Postgraduate Medical Journal (1985) 61, 1033-1038 Postgrad Med J: first published as 10.1136/pgmj.61.722.1033 on 1 December 1985. Downloaded from Review Article Intestinal pseudo-obstruction - a review Peter Isaacs' and Ali Keshavarzian2* 'Guy's Hospital, London SE] and2Hammersmith Hospital, London W12, UK. Introduction Pseudo-obstruction is an abnormality of intestinal After meals, mixing and an aborad movement of the motility severe enough to produce the clinical features contents is produced by segmenting contractions of of intestinal obstruction. the small bowel. Gastric emptying andjejunal motility Normal intestinal motility depends upon the are inhibited by the presence of nutrients in the distal modulation by nerves and hormones of the intrinsic small bowel (Spiller et al., 1984). rhythmical contractility of the smooth muscle syn- Abnormalities of gut motility may be produced by cytium. Contraction occurs when hyperpolarising disorders which affect the gut nerves, muscle layers, action potentials (spikes or electrical response activity, both of these or abnormal gut collagen and inter- Protected by copyright. ERA) coincide with the peaks of a continuously stitium (See Table I). fluctuating potential difference across the cell mem- brane (slow wave or electrical control activity, ECA) (Brading, 1979). Spike potentials are triggered by Table I Aetiological classification of intestinal pseudo- neurotransmitters but because of the fixed rate of the obstruction slow wave, the rhythmic contractile response also has a fixed maximum rate (3 c.p.m. in stomach, 12 c.p.m. Gut nerve dysfunction in duodenum and 8 c.p.m. in ileum of man; Duthie, Toxic - drugs, heavy metals, insecticides. 1979). The contraction ofthe intestinal muscle coats is Metabolic - amyloidosis, diabetes mellitus, porphyria, integrated by the myenteric plexus whose neurones paraneoplastic Inflammatory - Chagas' disease, varicella, Kawasaki lack specialized neuro-effector junctions but have disease, vancosities containing vesicles which release a wide Genetic - congenital and familial visceral neuropathy. variety of neurotransmitters including acetylcholine, noradrenaline, 5HT, peptides and purines (Burnstock, Gut muscle dysfunction 1982). Nicotinic cholinergic fibres mediate the rapid Familial visceral myopathy. http://pmj.bmj.com/ inhibitory descending reflex and purinergic fibres Dystrophia myotonica. mediate the slower excitatory descending pathway Polymyositis. (Hirst, 1979). The myenteric plexus also propagates the inter-digestive myoelectric complex (IMC) (Sarna Disorders affecting gut muscle andnervefunction Myxoedema. et al., 1981) which, in fasting man, sweeps aborally the Phaeochromocytoma. length of the small intestine at intervals of 15 to Hypoparathyroidism. 195 min, clearing the intestinal lumen. An abnormal Pregnancy. on September 30, 2021 by guest. bacterial population supervenes when IMC are aboli- Enteroglucagonoma. shed or absent. IMCs are stimulated by vagal activity Trauma. (Wingate, 1982), motilin (Itoh et al., 1981) and Jejuno-ileal bypass. suppressed by the ingestion of meals (Heppell et al., 1983). Disorders ofgut collagen andinterstitium Scleroderma. Radiation. Correspondence: P. Isaacs, M.D., M.R.C.P. Gastroen- Strongyloidosis. terology Unit, Victoria Hospital, Blackpool, FY3 8NR. Ehlers-Danlos syndrome. *Present address: Gastrointestinal Division, V.A. Medical Mesenteric panniculitis. Center, Baltimore, MD 21218, USA. Ceroidosis. Accepted: 14 May 1985 i) The Fellowship of Postgraduate Medicine, 1985 1034 P. ISAACS & A. KESHAVARZIAN Postgrad Med J: first published as 10.1136/pgmj.61.722.1033 on 1 December 1985. Downloaded from Disorders of gut nerves al., 1979). In endemic areas Chagas' disease produces widespread abnormality of gut function (Oliveira et Drugs which inhibit intestinal motility are the most al., 1983) due to the inflammatory reaction in the common cause of acute pseudo-obstruction, par- myenteric plexus (Smith, 1980). ticularly atropine-like drugs (Faulk et al., 1978), phenothiazines (Sriram et al., 1979), clonidine (Bear & Steer, 1976), tricyclic antidepressants and vincristine Disorders of gut muscle (Rosenberg & Caridi, 1983). A wide variety ofdiseases may damage the myenteric plexus but the mor- Failure of development of duodenal musculature has phological changes have to be extensive before symp- been reported (Handelsman et al., 1965) but inherited toms are produced (Smith, 1982). Congenital abnor- metabolic abnormalities of gut and muscle usually malities of the myenteric plexus are usually evident present later. Hereditary visceral myopathy is a degen- soon after birth because of vomiting or obstruction eration ofthe longitudinal muscle coat inherited as an and are sometimes associated with pyloric hypertro- autosomal dominant (Schuffier & Pope, 1977) Sub- phy and malrotation of the gut (Tanner et al., 1976), clinical achalasia-like abnormality of the oesophagus patent ductus arteriosus (Harris et al., 1976) or or intestinal pseudo-obstruction may occur in associa- urogenital tract plexus degeneration (megacystis- tion with urogenital tract smooth muscle degeneration microcolon-intestinal hypoperistalsis) (Jountz, 1981), (Faulk, 1978). An autosomal recessive-type associated which is probably due to cholinergic neurone loss. with ophthalmoplegia has been described (Anuras et Inherited generalized disease of the autonomic al., 1983). Investigations of relatives may help in nervous system (familial dysautonomia, Riley-Day making the diagnosis and in genetic counselling. syndrome) and congenital ganglioneuromatosis (Car- Skeletal muscle disorders such as dystrophia ney et al., 1976) lead to small bowel pseudo-obstruc- myotonica (Lewis & Daniel, 1981) and polymyositis tion, pyloric hypertrophy and megacolon probably (Patterson & Rios, 1959) may produce abnormal because both adrenergic and cholinergic nerves are gastric and duodenal motility. Protected by copyright. involved. Familial myenteric plexus degeneration (Schuffler et al., 1978) is associated with generalized evidence of Disorders affecting gut muscle and nerve autonomic dysfunction, ataxic gait and hypotonia. The pupils are hyper-reactive to pilocarpine suggest- A wide variety of metabolic abnormalities may affect ing a denervation hypersensitivity due to cholinergic both gut nerve and muscle function. Myxoedema neurone degeneration. Other families exhibit an slows small bowel transit (Shafer et al., 1984) achalasia-like abnormality of the oesophagus and sometimes producing acute pseudo-obstruction abnormal duodenal motility which responded normally, (Salerno & Grey, 1978). Congenital hypopara- to cholinergic agents suggesting deficiency of non- thyroidism may also produce intestinal pseudo-obs- adrenergic inhibitory mechanisms (Lewis et al., 1978). truction (Cockel et al., 1973). In diabetes mellitus, autonomic neuropathy is com- Pregnancy slows intestinal transit and renders IMCs mon, gastric emptying is frequently impaired (Loo et less frequent (Scott et al., 1983) and pseudo-obstruc- al., 1984) but small bowel pseudo-obstruction is rare. tion is particularly frequent following Caesarian sec- http://pmj.bmj.com/ Acute colonic dilatation may occur as a terminal event tion (Ravo et al., 1983). in severe diabetes (Paley et al., 1961). Abdominal pain, vomiting, constipation or pseudo- Intestinal pseudo-obstruction is also usually a ter- obstruction may be presenting symptoms of phaeo- minal event in secondary amyloidosis (Legge et al., chromocytoma (Turner, 1983) and the risks of 1970) but in familial amyloidosis with polyneuropathy, laparotomy in both this condition and in myxoedema episodic diarrhoea and constipation are typical. The are particularly high. amyloid deposition in gut nerve is responsible for the A unique patient with an enteroglucagonoma had abnormal gut response to cholinergic agents (Battle et chronic constipation and villous hyperplasia (Gleeson on September 30, 2021 by guest. al., 1979). Rarer degenerative disease of the myenteric et al., 1971) but no other peptide hormone secreting plexus such as glycolipid deposition in Fabry's disease tumours have been reported as causing pseudo-obs- (Friedman et al., 1984) and porphyria (Gorchein et al., truction. 1982) may present as pseudo-obstruction syndromes. The mechanism of acute pseudo-obstruction of the In Europe and North America infective neuropath- colon after blunt abdominal trauma with sepsis (Ad- ies are rare but have been reported following varicella dison, 1983) may be akin to pseudo-obstruction ofthe (Walsh, 1982) and in some sporadic cases ofmyenteric colon after jejunal-ileal bypass which is improved by plexus damage, immune reactions to an infective agent antibiotic therapy, suggesting that the bacterial similar to that seen in mucocutaneous lymph node production ofsubstances toxic to gut nerve and muscle syndrome (Kawasaki disease) is possible (Franken et is responsible. INTESTINAL PSEUDO-OBSTRUCTION 1035 Postgrad Med J: first published as 10.1136/pgmj.61.722.1033 on 1 December 1985. Downloaded from Abnormalities of gut collagen and interstitium horizontal sections through the gut wall fixed as a sheet (Smith, 1982) (Figure 1) will show abnormalities In comparison with skeletal muscle, smooth muscle not seen by routine histological techniques (Krish- contains much more collagen and disordered collagen namurthy & Schuffier, 1983) and special stains to metabolism produces intestinal dysmotility. show fibrous tissue and muscle will help differentiate The excess collagen in