chronic intestinal pseudo - obstruction syndrome ( cips ) is a rare , severe gastrointestinal motility disorder , characterized by recurrent or continuous signs and symptoms suggesting mechanical bowel obstruction in the absence of a lesion that occludes the intestinal lumen [ 3 , 14 , 15 ] . although the absence of mechanical obstruction is imperative for the initial diagnosis of cips , true mechanical obstruction is a possible complication . in cips patients , this condition is particularly hard to recognize because the presentation is indistinguishable from common cips symptoms . here , an 8-year - old boy , diagnosed at 3  years of age with hypoperistaltic dysmotility of intestines and bladder as a variant of cips , was admitted to our tertiary pediatric hospital . extensive histopathological examination showed no underlying disease . in the past , he had undergone two operations of the bladder ( size reduction and valve resection ) and biopsies of the bowel . neurological symptoms were absent , and no other signs of involvement of mitochondrial disorders were observed . at admission , the boy presented with abdominal pain , abdominal distension , increased gastric retention , and decreased defecation frequency . initially , these symptoms were interpreted as an exacerbation of cips and conservative treatment with gastric decompression by nasogastric tube was started . during hospitalization , the boy clinically deteriorated with increasing gastric retention , abdominal distension , and severe crampy abdominal pain . the ineffectiveness of the conservative treatment and meanwhile clinical deterioration were suggestive for mechanical obstruction . an extremely dilated bowel loop came into view , with a diameter of approximately 20  cm ( fig .  1 ) . it appeared to involve the majority of the transverse colon , which was rotated three times around itself . possibly , this was a result of torsion of the dilated and fluid - filled transverse colon . after derotation of the volvulus , a suction device was placed rectally for decompression and 3  l of intraintestinal fluid could be drained . during the postoperative course , the patient recovered quickly.fig . an 8-year - old boy with chronic intestinal pseudo - obstruction syndrome presented with deteriorating symptoms of mechanical obstruction without improvement on conservative treatment . at laparotomy , an extremely dilated transverse colon with a diameter of about 20  cm was found as a result of transverse colonic volvulus volvulus in an 8-year - old boy with chronic intestinal pseudo - obstruction syndrome . an 8-year - old boy with chronic intestinal pseudo - obstruction syndrome presented with deteriorating symptoms of mechanical obstruction without improvement on conservative treatment . at laparotomy , an extremely dilated transverse colon with a diameter of about 20  cm was found as a result of transverse colonic volvulus a 2-year - old boy , with cips and a high - output ileostomy for which no specific etiologic factor had been found , was admitted to our hospital . cips had been diagnosed in the first few months following premature birth , and the patient had since been dependent of total parenteral nutrition ( tpn ) . however , ophthalmoplegia , polyneuropathy , and other neurological symptoms were absent ; urine thymidine was normal , and on mri , no leukoencephalopathy was seen . because mngie syndrome was therefore deemed unlikely , mngie gene analysis was not performed . at this time , he presented at the emergency department with a 3-day course of abdominal pain , progressive abdominal distension , fluctuating febrile temperature , coughing , and malaise . the symptoms were first thought to be part of an exacerbation of cips . however , the ileostomy production had decreased over the past few days , which was in contradiction with the usual output of 3  l / day . at physical examination , an ill child was seen with a need for oxygen support and a painful and severely distended abdomen . suspicion of a mechanical obstruction arose , and gastric decompression by nasogastric tube was not awaited because of the severity of illness of the patient . at laparotomy , dilated fluid - filled bowel loops were seen , which were caused by a volvulus of the small intestine . the cause seemed to be torsion of the fluid - filled loops of decompensated bowel . the volvulus was derotated , and the intestine was drained with a suction device via the ileostomy . cips is characterized by impaired propulsion of contents of the gastrointestinal tract , which results in the clinical picture of intestinal obstruction . symptoms at first presentation in cips patients are abdominal distension ( 98% ) , vomiting ( 91% ) , constipation ( 77% ) , failure to thrive ( 62% ) , abdominal pain ( 58% ) , and diarrhea ( 31% ) . radiographic evidence of dilated bowel with air  fluid levels is obligatory to diagnose cips [ 14 , 15 ] . cips is either a primary condition or secondary to a wide range of pathological conditions such as systemic diseases with gastrointestinal involvement , electrolyte disorders , toxic , viral , parasitic , or immune - mediated causes . primary cips can be congenital or acquired , and underlying pathohistological abnormalities are classified as neuropathy , mesenchymopathy , or myopathy [ 6 , 15 ] . these entities respectively refer to affected ( intrinsic and extrinsic ) gastrointestinal nerve pathways , interstitial cells of cajal , and smooth muscle cells ( table  1 ) . extent of involvement of the tract varies from merely a small region to the entire tract including esophagus and stomach . in the second case , the affected part of the gastrointestinal tract was extended from stomach to colon.table  1pathogenesis of chronic intestinal pseudo - obstruction syndrome [ 6 , 7 , 10 , 11]entityaffected cellspathogenesisunderlying diseaseneuropathyenteric , sympathetic , or parasympathetic neuronsinflammation of myenteric plexus , submucous plexus , or axons ( infiltration of lymphocytes , humoral response with antineuronal bodies)infection , e.g. , chagas disease , cmv , or ebv infectionneurological disease , e.g. , encephalomyeloneuropathyautoimmune , e.g. , sclerodermainflammatory diseases , e.g. , inflammatory bowel diseaseparaneoplastic to , e.g. , small cell carcinoma , carcinoid , neuroblastoma , thymomaendocrine , e.g. , hypothyroidismother , e.g. , amyloidosisidiopathicdegeneration of neurons ( reduction in neurons , structural abnormalities , proliferation of glial cells)endogenous and exogenous stimuli leading to damage and loss of enteric neurons :  e.g. , altered calcium signaling , mitochondrial disorders , free radicals , and reduced gene expression of b cell lymphoma 2 gene leading to neuronal apoptosishyperganglionosise.g . neuronal intestinal dysplasia , and men2bmesenchymopathyiccaltered icc network , i.e. , decreased or increased presence of icc and structural abnormalitiesmyopathysmooth muscle cells of the circular and longitudinal muscle layers of the intestinal wallabnormal architecture of muscle layers ( e.g. , additional muscle layer ) , degeneration ( fibrosis , vacuolization , inclusion bodies ) , and -actin abnormalities / deficiencyprimary visceral myopathymuscular dystrophy , e.g. , duchenne 's diseasemyotonic dystrophymitochondrial disorders , e.g. , melasautoimmune disordersothercmv cytomegalovirus ; ebv epstein  barr virus ; icc interstitial cells of cajal ; melas mitochondrial myopathy , encephalopathy , lactic acidosis , stroke - like episodes ; men2b multiple endocrine neoplasia , type 2b pathogenesis of chronic intestinal pseudo - obstruction syndrome [ 6 , 7 , 10 , 11 ] cmv cytomegalovirus ; ebv epstein  barr virus ; icc interstitial cells of cajal ; melas mitochondrial myopathy , encephalopathy , lactic acidosis , stroke - like episodes ; men2b multiple endocrine neoplasia , type 2b extra - gastrointestinal manifestations may also be apparent in some forms of primary cips , for example , dysmotility of the urinary tract as in the first case . an example is mngie , which is a rare , autosomal recessive syndrome affecting thymidine phosphorylase activity . gastrointestinal manifestations , such as cips , are usually the first sign in this progressive disease [ 12 , 16 ] . the frequency of mitochondrial disorders as cause of cips is however not known well ; a recent report found underlying mitochondrial defects in one third of patients . the management of cips depends on the underlying cause of pseudo - obstruction . in every case if enteral nutrition is not possible due to insufficient motility or enteral uptake , tpn is a necessity . severely affected individuals may become chronically tpn dependent , but long - term tpn is related to high morbidity and mortality [ 7 , 9 ] . pharmacological therapy , such as prokinetics , may help in controlling symptoms [ 3 , 5 ] . a frequent complication of cips is bacterial overgrowth due to stasis of intestinal contents , causing malabsorption and in some cases sepsis . intermittent antibiotic treatment is used to minimize the risk of bacterial overgrowth [ 5 , 14 ] . gastrostomies and enterostomies are constituted for intermittently venting dilated bowel and can be used for the administration of nutrition . in localized disease , resection of the affected gastrointestinal tract can be a curative treatment . in patients with total gastrointestinal tract involvement and who are entirely tpn dependent , intestinal transplantation is the ultimate treatment modality to achieve a tpn - independent life . 5060% of cips patients were diagnosed via a laparotomy excluding mechanical obstruction [ 7 , 9 ] . those patients presenting with an acute onset suggestive for mechanical obstruction had a high risk to undergo laparotomy . because previous surgery is a risk factor for adhesions that might cause mechanical obstruction , a following obstructive episode is difficult to interpret . the decision for another , possibly unnecessary , intervention might be made on these grounds . in the other study , procedures performed during primary surgical intervention did not relieve symptoms in over 50% of patients . reconstituting continuity of the gastrointestinal tract in patients with an effective decompression ileostomy is discouraged since in diffuse disease , this may lead to new episodes of obstruction [ 8 , 9 ] . thus , it should be realized that surgical interventions are often unsuccessful in cips patients and that multiple interventions might enhance the risk for multiple obstructive episodes on the long term . moreover , besides possibly generating adhesions that predispose to mechanical obstruction , surgical interventions elicit the risk of general surgical complications and may lead to postoperative paralytic ileus , which contributes to dysmotility . although mechanical obstruction is normally absent in cips patients , it can be a complication of cips , especially after multiple interventions . as illustrated by our two cases , adhesions are not the only cause of mechanical obstruction ; volvulus due to torsion of fluid - filled bowel loops may occur as well . stasis of intestinal contents is common in cips , and chronic dilatation leads to decompensation and elongation of the bowel , further impairing motility . when fluid and air accumulate in these decompensated loops , torsion caused by mechanical forces is possible . another report summarized transverse colon volvulus in children with different underlying diseases causing elongation and distension of the bowel , e.g. , irregular bowel function in mental retardation and chronic constipation . furthermore , altaf et al . reported eight patients with colonic volvulus as a complication of cips or chronic intractable constipation . thus , mechanical obstruction by volvulus of decompensated bowel or strangulation due to adhesions should be part of the differential diagnosis in exacerbations of cips . distinguishing an event of mechanical obstruction from the  normal  pseudo - obstructive episodes is difficult . as illustrated by our two cases , recognition of true mechanical obstruction is however important as it usually requires acute surgical intervention and is potentially life threatening when treatment is omitted . awareness should be raised when little or no improvement is seen on standard treatment , such as bowel decompression , in exacerbations with abdominal pain and distension , vomiting , and decreased defecation . signs that point more towards mechanical obstruction are extreme dilatation , signs of peritonism , and pain that is related to specific episodes of aggravating obstructive symptoms . furthermore , one should be cautious when abdominal distention at physical examination and bowel dilatation on plain radiographic examination are exceeding the usual proportions for the patient in question , such as in our cases . although explorative laparotomies should still be highly discouraged in cips , sometimes the decision for surgical intervention has to be made if there is enough evidence of true mechanical obstruction . contrast studies and ct scans are especially helpful to exclude an occluding lesion during obstructive periods . the use of these techniques before proceeding to surgical intervention is therefore recommended as well as initially attempting conservative treatment with bowel decompression by nasogastric suction . in conclusion , these two cases illustrate that awareness of the possibility of true mechanical obstruction , as a complication of cips , is needed in cips patients without improvement of an exacerbation on conservative treatment . it is a severe , potentially life - threatening condition and usually requires surgical intervention .
chronic intestinal pseudo - obstruction syndrome ( cips ) is a severe motility disorder of the gastrointestinal tract that presents with continuous or recurrent symptoms and signs of intestinal obstruction without evidence of a structural lesion occluding the intestinal lumen . 
 mechanical obstruction might occur in these patients as well but is typically difficult to distinguish from an exacerbation of cips . 
 we report two pediatric cases in which mechanical obstruction by volvulus mimicked an exacerbation of cips , requiring surgical intervention . 
 conclusion : awareness of the possibility of true mechanical obstruction in cips patients during an exacerbation episode is needed , as this is a severe condition and usually requires surgical intervention .