Acute colonic pseudo-obstruction (ACPO) is a severe form of colonic dysmotility and is associated with considerable morbidity. The pathophysiology of ACPO is considered to be multifactorial but has not been clarified. Although colonic motility is commonly assumed to be hypoactive, there is little direct pathophysiological evidence to support this claim.

A 56-year-old woman who developed ACPO following spinal surgery underwent 24 h of continuous high-resolution colonic manometry (1 cm resolution over 36 cm) following endoscopic decompression. Manometry data were analyzed and correlated with a three-dimensional colonic model developed from computed tomography (CT) imaging.

The distal colon was found to be profoundly hyperactive, showing near-continuous non-propagating motor activity. Dominant frequencies at 2-6 and 8-12 cycles per minute were observed. The activity was often dissociated and out-of-phase across adjacent regions. The mean amplitude of motor activity was higher than that reported from pre- and post-prandial healthy controls. Correlation with CT imaging suggested that these disordered hyperactive motility sequences might act as a functional pseudo-obstruction in the distal colon resulting in secondary proximal dilatation.

This is the first detailed description of motility patterns in ACPO and suggests a novel underlying disease mechanism, warranting further investigation and identification of potential therapeutic targets.

To critically review the literature addressing the definition, epidemiology, aetiology and pathophysiology of acute colonic pseudo-obstruction (ACPO).

A systematic search was performed to identify articles investigating the aetiology and pathophysiology of ACPO. A narrative synthesis of the evidence was undertaken.

No consistent approach to the definition or reporting of ACPO has been developed, which has led to overlapping investigation with other conditions. A vast array of risk factors has been identified, supporting a multifactorial aetiology. The pathophysiological mechanisms remain unclear, but are likely related to altered autonomic regulation of colonic motility, in the setting of other predisposing factors.

Future research should aim to establish a clear and consistent definition of ACPO, and elucidate the pathophysiological mechanisms leading to altered colonic function. An improved understanding of the aetiology of ACPO may facilitate the development of targeted strategies for its prevention and treatment.

Acute pseudo-obstruction is a rare complication in burns patients. An awareness of the factors implicated in its pathogenesis such as prolonged bed rest, narcotic medications, hypokalaemia, sepsis and surgery (all commonly associated with burns patients) is essential if this condition is to be avoided. Early diagnosis, prokinetic and cathartic agents, and aggressive endoscopic intervention are essential to halt the progression of caecal dilatation. Excisional surgery and stoma formation are necessary for salvage of complicated colonic pseudo-obstruction.

The syndrome of acute colonic pseudo-obstruction is well delineated but its aetiology remains poorly understood and patients are still treated inappropriately. This article reviews the pathogenesis and surgical management of this condition. Early diagnosis is stressed as a pivotal factor in reducing morbidity and mortality.

Pseudo-obstruction of the colon is characterized by an adynamic unobstructed colon which rapidly progresses to marked dilatation of the cecum and transverse colon. Disagreements exist regarding the etiology or pathogenesis of this syndrome; it has been associated with metabolic, traumatic, postoperative, and idiopathic causes. In reviewing the literature we have concluded that in pseudo-obstruction of the colon after cesarean section, the mean age of occurrence is 35 years. The symptoms occur in the first 72 hours after operation. Straight x-ray examination of the abdomen is the most useful diagnostic measure. All cecal perforations occurred by the fifth postoperative day. For this reason, we recommend early diagnosis and prompt surgical intervention before that time. In cases when the cecal distention is 12 cm or more, decompression is urgent.

Four additional cases of Ogilvie's syndrome (acute colonic pseudo-obstruction), representing the first cases described in Italy, are reported. The medical literature concerning the subject is also thoroughly reviewed. Ogilvie's syndrome is an acute massive dilatation of the large bowel without organic obstruction of the distal colon. Three hundred and fifty-one cases have been described in the literature to date. Eighty-eight per cent of the cases were associated with various extracolonic affections (metabolic and organ dysfunctions, postoperative and posttraumatic states, etc.). Twelve per cent of cases were not associated with known disorders and were defined as idiopathic. The pathophysiology of the syndrome is still unknown. Ogilvie, who first described the syndrome in 1948, suggested an imbalance between the sympathetic and parasympathetic innervation of the colon: this neurogenic hypothesis has been shared by other authors, although explanations may differ slightly. The clinical and radiologic picture closely resembles mechanical obstruction of the large bowel. The most marked dilatation usually takes place in the right colon and cecum: if the distended cecum reaches a diameter larger than 9 to 12 cm, perforation is likely to occur; if perforation occurs, the mortality rate increases from 25 to 31 per cent to about 43 to 46 per cent. If conservative management fails to control the dilatation and cecal rupture is impending or suspected emergency surgery is indicated, the surgical procedure of choice is dictated by the general conditions of the patient as well as by the intestinal findings: operation may consist of cecostomy, colostomy, or right hemicolectomy or simply emptying the bowel.

Pseudo-obstruction of the colon, or Ogilvie's syndrome, is characterized by an adynamic, dilated, unobstructed colon, the exact cause of which remains obscure. Although several precipitating factors have been described in the literature, we have observed three patients whose pseudo-obstruction of the colon occurred during interstitial and intracavitary pelvic irradiation. Such a cause has not been noted previously. Pseudo-obstruction of the colon can have serious consequences if it is not recognized early and treated vigorously.

Seven patients with acute and progressive abdominal distension secondary to massive cecal and right colon ileus are analyzed. Five had pseudoobstruction of the colon and two had cecal volvulus. Two of the patients with pseudoobstruction and one with cecal volvulus died from preexisting diseases. Pseudoobstruction of the colon is not a rare complication of elderly, sick, bedridden patients. Differential diagnoses include cecal and sigmoid volvulus and acute gastric dilation. Initial conservative therapy is warranted if no peritoneal signs are present. If the cecal diameter is more than 12 cm, colonoscopic decompression with a fiberscope should be attempted. If unsuccessful, tube cecostomy will provide curative, life-saving therapy even if taenia splitting is present. Perforation or widely scattered areas of necrosis make resection mandatory.

Pseudoobstruction of the colon is a specific variety of adynamic ileus. Its characteristic clinical presentation is severe cramping lower abdominal pain, a massively distended abdomen, and a characteristic x-ray picture. Thirty-five patients with this disease complex have been reviewed, and their surgical and medical therapy is discussed. Guidelines for continued medical versus surgical intervention are suggested. Two patients underwent decompression with the colonoscope. Its use and a possible hazard of the procedure are discussed. For those patients who develop pseudoobstruction after trauma or surgery, a pathophysiologic explanation is offered. The possible role of prostaglandin abnormality in the genesis of pseudoobstruction is also discussed.

Caecal rupture due to colonic ileus is rare and has a mortality rate of 43 per cent. Three new cases are presented and the 18 previously reported cases are reviewed. The disease has always occurred in association with another illness, has usually afflicted patients over the age of 55 and has only resulted when the caecum was at least 9 cm in diameter. The technique of 'blow-hole' caecostomy, a method for decompressing the distended caecum, is described.