Postprandial colonic transit and motor activity in chronic constipation

The aim of this study was to correlate colonic motility and transit in patients with constipation and symptoms of the irritable bowel syndrome. Studies were performed in 16 patients with constipation and compared with the results in 12 healthy subjects. Intraluminal pressure was measured with perfused catheter ports in the transverse colon, splenic flexure, and descending and sigmoid colon. Movement of the luminal contents was measured by following the movement of Technetium-99m-DTPA that was instilled as a bolus in the splenic flexure. In both healthy subjects and patients with constipation there was no movement of the intraluminal tracer and no increase in intraluminal pressure during fasting. After eating a meal, healthy subjects and one group of the constipated patients had an increase in the radioactive marker in the transverse colon (p less than 0.03) and in the sigmoid colon (p less than 0.03). The movement of the intraluminal contents was associated with a positive pressure gradient between the descending colon and the transverse and sigmoid colon. There was no retrograde movement of the intraluminal contents and no postprandial increase in intraluminal pressure in the second group of patients with constipation. In healthy subjects, propagating contractions, which were associated with the rapid movement of intraluminal contents, began 60 min after eating. There were no propagating contractions in patients with constipation. These studies suggest that (a) the movement of intraluminal contents in healthy and constipated patients is determined by the postprandial pressure gradients within the colon, and (b) the propagating contraction is necessary for a normal bowel habit.     

Cephalic phase of colonic pressure response to food.

A cephalic phase of colonic pressure response to food was sought in five normal subjects (mean age (22.6) years, 22-24), studied on six separate occasions by recording intraluminal pressures in the unprepared sigmoid colon. Gastric acid secretion was measured simultaneously by continuous aspiration through a nasogastric tube. After a 60 minute basal period, one of five 30 minute food related cephalic stimuli, or a control stimulus was given in random order; records were continued for a further 120 minutes. The cephalic stimuli were: food discussion, sight and smell of food without taste, smell of food without sight or taste, sight of food without smell or taste, and modified sham feeding; the control stimulus was a discussion of neutral topics. Colonic pressures were expressed as study segment activity index (area under curve, mm Hg.min) derived by fully automated computer analysis. Gastric acid output was expressed as mmol/30 min. Food discussion significantly (p < 0.02, Wilcoxon's rank sum test) increased colonic pressure activity compared with control or basal activity. Smell of food without sight or taste also significantly (p < 0.03) increased the colonic pressure activity compared with control and basal periods. Sham feeding and sight and smell of food without taste significantly (p < 0.02 and p < 0.03) increased colonic pressures compared with control but not basal activity. The increase in colonic activity after sight of food without smell or taste was not significantly different from control or basal activity (p = 0.44 and p = 0.34). Food discussion was the strongest colonic stimulus tested. Food discussion and sham feeding significantly (p<0.02) stimulated gastric acid output above control and basal values. Sight and smell of food without taste significantly (p<0.02) increased acid output above basal. Smell of food without sight or taste and sight of food without smell or taste did not significantly (p=0.06, p=0.34) increase acid output. In contrast with the effect on colonic pressures, sham feeding was the best stimulus of acid output. Increased colonic pressure activity after food discussion correlated significantly (r=0.45, p<0.02) with gastric acid output. There was no correlation (r=-0.1, p>0.5) between colonic pressure activity and gastric acid output in the control study. These data show that there is a cephalic phase of the colonic response to food.     

Studies on the Defecation Reflex in Man

In patients with cecostomies and in patients with urinary bladder substitutes obtained from either the sigmoid colon or the cecum, the motor activity in different parts of the large bowel was recorded with the aid of open tip tubes and a pressure-recording apparatus after administration of a contact laxative (Dulcolax®). Administration of Dulcolax® into the cecum of patients with cecostomy produced motor activity locally as well as in the transverse colon and in the sigmoid. When the drug was administered into the cecum of patients with isolated cecal bladder replacements, motor activity was recorded in the cecum but not in the sigmoid. Rectal application of Dulcolax® initiated motor activity in the intact sigmoid as well as in the isolated sigmoid bladder substitute but not in the cecum in patients with cecostomies nor in the cecal bladder replacements. The experiments indicate that only the left colon is engaged in the defecation mechanism elicited by rectal stimulation. The motor response in the left colon after rectal stimulation is mediated by a reflex with its afferent limb from the rectal ampulla. The motor response in the sigmoid after cecal stimulation is elicited by impulses mediated by intrinsic nervous pathways in the intestinal wall.     

Rectal and colonic studies after resection of the sigmoid for diverticular disease

Spontaneous basal rectal activity, recorded after resection of the sigmoid colon for diverticular disease, was more than twice the normal.The rectum of post-resection cases yielded a markedly exaggerated overall response to prostigmine, in addition to producing abundant fast wave patterns.The response to stretch of the apparently normal colonic muscle remaining after resection of the sigmoid for diverticular disease resembled unresected diverticular segments, though less in degree, suggesting that a fundamental disorder of colonic muscle may be involved in the aetiology of colonic diverticula.     

人参调脾散对腹泻型肠易激综合征患者结肠黏膜5羟色胺3受体mRNA表达的影响

[目的]检测腹泻型肠易激综合征（IBS-D）患者结肠组织5羟色胺3受体mRNA（5-HT3RmRNA）的表达水平,探讨中药人参调脾散治疗IBS-D的作用机制。[方法]采用逆转录-聚合酶链式反应（RT-PCR）方法分析IBS-D患者治疗前后及正常人（对照组）乙状结肠黏膜5-HT3RmRNA表达水平的变化。[结果]mS-D患者治疗前5-HT3RmRNA表达水平较对照组显著增高,2组比较差异有统计学意义（P〈0．05）;经人参调脾散治疗后5-HT3RmRNA表达水平减低,与对照组比较差异无统计学意义（P〉O．05）;IBS-D患者治疗前后5-HT3RmRNA表达水平自身比较差异有统计学意义（P〈0．05）。[结论]人参调脾散能通过下调IBS-D患者结肠黏膜5-HT3RmRNA表达,降低5-HT3R活性,达到治疗IBS-D的作用。     

Effect of eating on colonic motility and transit in patients with functional diarrhea. Simultaneous scintigraphic and manometric evaluations

The aim of this study was to correlate colonic motility with transit in 8 patients with functional diarrhea compared to 12 healthy subjects. Intraluminal pressure was measured with perfused catheter ports in the transverse colon, splenic flexure, and descending and sigmoid colons. Transit of the luminal contents was measured by following the movement of 99mTC-diethylenetriaminepentaacetic acid instilled as a bolus in the splenic flexure. In patients with diarrhea, the intraluminal marker moved in and out of the transverse and sigmoid colon regions of interest during fasting, unlike healthy subjects, in whom the marker remained in the splenic flexure. After eating, radioactivity immediately increased in both the transverse and sigmoid colons in healthy subjects. In the patients with diarrhea, eating did not alter the marker movement into the different regions of the colon compared with fasting. Within 100 minutes of eating, the intraluminal marker almost disappeared from the regions of interest in patients with diarrhea. Postprandial colonic nonpropagating contractions increased in each region of the colon in healthy subjects; there was only a small postprandial increase in colonic motility in patients with diarrhea. However, the numbers of fasting and postprandial propagating contractions were increased in patients with diarrhea compared with healthy subjects (P less than 0.02). Each propagating contraction moved more tracer in patients with diarrhea than in healthy subjects (P less than 0.05). These studies suggest that (a) in patients with diarrhea, the fluctuation of marker in both transverse and sigmoid colons during the fasting and postprandial periods is associated with decreased nonsegmenting contractions and frequent propagating contractions; and (b) in healthy subjects, the intraluminal marker moved after eating because of a pressure gradient caused by nonpropagating contractions.     

Alterations in colonic motility and relationship to pain in colonic diverticulosis.

BACKGROUND AND AIMS: Although the pathophysiologic basis of colonic diverticular disease is understood incompletely, there is agreement that abnormal colon motility probably plays a major role. However, several different abnormalities have been reported in such patients. The purpose of this study was to assess whether patients with diverticulosis display an abnormal duration of regular colonic contractile patterns, which has been observed in other conditions characterized by spasticity of the viscus, such as the irritable bowel syndrome. METHODS: Twelve patients with symptomatic uncomplicated diverticular disease entered the study and underwent 24-hour colonic manometric recordings using a standard technique. The duration of regular contractile patterns was compared with that recorded in 20 healthy volunteers. RESULTS: Patients with diverticulosis had a significant increase of the duration of regular patterns of phasic pressure activity compared with healthy controls (31% vs. 6.4%, P < .001). In both groups, the 2- or 3-cycles-per-minute activity represented more than 80% of such activity, especially in the sigmoid colon. More than 30% of patients, but none of the controls, reported episodes of abdominal pain (cramping lower abdominal pain with characteristics similar to those experienced at home) during the occurrence of a regular colonic contractile pattern. This was significant by symptom association probability criteria. CONCLUSIONS: Patients with symptomatic uncomplicated colonic diverticulosis displayed increased duration of rhythmic, low-frequency, contractile activity, particularly in the segments bearing diverticula. These regular rhythms are associated significantly with reporting of abdominal pain.     

Intact colonic motor response to sudden awakening from sleep in patients with chronic idiopathic (slow-transit) constipation

PURPOSE: There are few data about the relationships between colonic motor behavior and higher brain functions, such as sleep. Previous studies were done in healthy subjects, and it is unknown whether patients with functional motor disorders of the colon behave differently. This study was designed to characterize colonic motor activity in patients with constipation, both during sleep and after sudden awakening, and to compare it with that of healthy subjects. Our working hypothesis was that patients with constipation would have an impaired response to sudden awakening. PATIENTS AND METHODS: Twelve chronically constipated women, 22 to 49 years old, were recruited for the study, and their data were compared with those obtained from 12 healthy female volunteers, 21 to 38 years old. Manometric studies were performed in the descending and sigmoid colon for 30 minutes during sleep (immediately before awakening) and 30 minutes after being awakened suddenly. A motility index was calculated before and after the stimulus. RESULTS: In both groups motility in the descending and the sigmoid colon was almost absent during sleep and significantly increased after sudden awakening. No difference in postawakening values was found between patients with constipation and controls. CONCLUSIONS: In patients with chronic constipation, the brain-gut control of some fundamental mechanisms governing colonic motility is preserved. These data suggest that the alterations of colonic motility described in chronic constipation may be caused by an intrinsic dysfunction of the viscus.     

Effect of a corticotropin releasing hormone receptor antagonist on colonic sensory and motor function in patients with irritable bowel syndrome

BACKGROUND AND AIMS: Corticotropin releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with an exaggerated response to stress. We hypothesised that peripheral administration of alpha-helical CRH (alphahCRH), a non-selective CRH receptor antagonist, would improve gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation in IBS patients. METHODS: Ten normal healthy subjects and 10 IBS patients, diagnosed according to the Rome II criteria, were studied. The tone of the descending colon and intraluminal pressure of the sigmoid colon were measured at baseline, during rectal electrical stimulation (ES), and at recovery after administration of saline. Visceral perception after colonic distension or rectal ES was evaluated as threshold values on an ordinate scale. The same measurements were repeated after administration of alphahCRH (10 micro g/kg). RESULTS: ES induced significantly higher motility indices of the colon in IBS patients compared with controls. This response was significantly suppressed in IBS patients but not in controls after administration of alphahCRH. Administration of alphahCRH induced a significant increase in the barostat bag volume of controls but not in that of IBS patients. alphahCRH significantly reduced the ordinate scale of abdominal pain and anxiety evoked by ES in IBS patients. Plasma adrenocorticotropic hormone and serum cortisol levels were generally not suppressed by alphahCRH. CONCLUSION: Peripheral administration of alphahCRH improves gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation, without affecting the hypothalamo-pituitary-adrenal axis in IBS patients.     

Morphology of myenteric plexuses in the human large intestine: comparison between large intestines with and without colonic diverticula

BACKGROUND: Large intestines with diverticula exhibit functionally abnormal peristaltic activity and elevated luminal pressure that may indicate functional changes in the myenteric plexus; however, no studies have investigated the characteristics of either normal or diverticula myenteric plexuses. METHODS: Tissue specimens obtained from 93 colorectal cancer patients without diverticula, 14 patients with perforated diverticulitis, and 12 colorectal cancer patients with asymptomatic diverticula were included in this study. Myenteric plexuses and ganglion cells were counted per centimeter, and the area and maximum diameter of the nuclei of ganglion cells were measured using an image analyzer. RESULTS: The number of myenteric plexuses and ganglion cells per centimeter was significantly higher in the descending colon, sigmoid colon, and rectum than in the cecum, ascending colon, and transverse colon. The area of the nuclei of ganglion cells was significantly larger in the descending colon and sigmoid colon than in the cecum and ascending colon. Compared with large intestines without diverticula, the number of myenteric plexuses was significantly higher in large intestines with diverticula, whereas the number of ganglion cells decreased in both right-sided and left-sided large intestines with perforated diverticulitis or asymptomatic diverticula. The area of the nuclei of ganglion cells was significantly smaller in large intestines with diverticula. CONCLUSION: The morphology of myenteric plexuses and the ganglion cells differs significantly among segments of the human large intestine. Large intestines with diverticula had significantly more plexuses but significantly fewer ganglion cells than large intestines without diverticula. The area of the nuclei of ganglion cells was also significantly smaller in large intestines with diverticula. Further studies are required to clarify how these changes are related to intestinal function and how they are involved in the etiology of diverticulosis.     

Diagnosis and treatment of spontaneous colonic perforation： Analysis of 10 cases

AIM： To investigate the etiology, diagnosis and treatment of spontaneous perforation of the colon.
METHODS： The clinical data of 10 cases of spontaneous perforation of the colon, observed at Fuding hospital from January 2004 to December 2007, were analyzed retrospectively.
RESULTS： The mean age at onset was 65 years （range from 45 to 73）. Seven patients had a history of chronic constipation. All patients complained of sudden lower abdominal pain. The perforation occurred after coloclysis and administration of senna leaves in two patients. Nine patients had signs of peritoneal irritation. Seven cases underwent abdominal paracentesis, which was diagnostic in six. Only one case was definitely diagnosed prior to surgery. One patient underwent neoplasty of the colon, another a partial resection of colon, six a neoplasty of the colon plus sigmoid colostomy, and two underwent Hartmann surgery. All perforation sites were opposite to the mesenteric edge. The perforation sites were located on descending colon in one case, sigmoid colon in three cases, and rectosigmoid colon in six cases. In five patients, surgical pathological examination was consistent with the microscopical changes of colonic perforation caused by feces. Three patients died after surgery.
CONCLUSION： Spontaneous perforation of the colon most commonly occurs among the elderly with chronic constipation. Abdominal paracentesis is helpful for the diagnosis. The perforation site is located opposite to the mesenteric edge. Sigmoid colon and rectosigmoid colon are the most frequent locations. Neoplasty of the colon and sigmoid colostomy are the most frequent treatment. The prognosis is bad and the mortality rate after surgery is high.     

Sigmoidismus or Sigmoid-Rectosigmoid Junction Dyssynergia Syndrome A New Clinicopathologic Entity

We previously reported that the rectosigmoid junction (RSJ) reacts to sigmoid contraction by opening and to rectal contraction by closing [28]. The current communication presents 19 patients (age 43.3 - 6.2 years; 15 women, 4 men) complaining of chronic idiopathic constipation which proved to be due to sigmoid-rectosigmoid junction incoordination. Ten healthy volunteers matching the patients in age and gender, acted as controls. Intestinal transit test, defecography, and EMG of the external anal sphincter and levator ani muscle were performed. The pressures in the sigmoid colon, rectosigmoid junction, rectum and rectal neck (anal canal) in response to individual sigmoid or rectal distension in increments of 10 ml CO₂ were determined. In the patient group, the intestinal transit test showed the markers accumulating in the sigmoid colon. The basal pressures in the sigmoid colon, rectosigmoid junction, rectum and rectal neck were similar in the patient and control groups. In the healthy controls mean sigmoid distension with 93.6 -, 3.5 ml effected sigmoid contraction, rectosigmoid junction relaxation and balloon expulsion to the rectum while in the patients effected no response. The sigmoid colon pressure in the patients rose at a mean distending volume of 108.6 - 7.3 ml and was elevated up to a volume of 136.6 - 10.8 ml but the rectosigmoid junction pressure showed no change and the balloon was not dispelled. Rectal distension in controls produced rectosigmoid junction pressure rise, while in the patients showed no response. Sigmoidismus or failure of the rectosigmoid junction to dilate upon sigmoid distension was diagnosed. Sigmoidoplasty, performed in 14/19 patients, cured 11. Sigmoidismus is a new clinicopathologic entity that should be considered in the diagnosis of chronic idiopathic constipation. Open rectosigmoidoplasty effected cure in 78.5%; the procedure is suggested to be performed laparoscopically.     

Autonomic control of colonic tone and the cold pressore test.

BACKGROUND: Cardiovascular responses to cold stimulation are well characterised. It is unclear, however, whether cold pain stimulates responses in colonic tone in the transverse and sigmoid regions. AIMS: To assess the effects of cold stimulation on tone nd motility in the transverse and sigmoid colon and on cardiovascular autonomic activity. METHODS: Phasic and tonic motility of the transverse and sigmoid colon, pulse rate, and beat to beat pulse variability (which are measures of centrally mediated changes in autonomic function) were measured before, during, and after a standard cold pressor test in 22 healthy volunteers. RESULTS: Cold pain induced a significant increase in colonic tone but not phasic contractility in the transverse and sigmoid regions. Simultaneously, cold pain increased pulse interval variability. CONCLUSION: The findings are consistent with the hypotheses that cold pain produces coactivation of both the sympathetic and parasympathetic limbs of the autonomic nervous system and that cold induced changes in colonic tone are temporally associated with alterations in central autonomic nervous activity.     

Angiomyolipoma of the colon: a new entity in colonic polypoid lesions

A 67-year-old man with angiomyolipoma on the sigmoid colon is reported. The colonic polyp was pedunculated and diagnosed histologically after endoscopic polypectomy. Angiomyolipoma is one of the benign hamartomas arising principally in the kidneys of patients with or without tuberous sclerosis. Extrarenal angiomyolipoma is rare and this may be the first report of colonic angiomyolipoma.     

Dynamic scanning defines a colonic defect in severe idiopathic constipation.

A technique is described in which a chemical stimulus applied to the mucosa of the right colon is used to assess colonic motor function. Peroral intubation of the right colon was achieved using a fine polyvinylchloride (PVC) tube. Bisacodyl was used to initiate colonic motor activity, and colonic transit was monitored using 99mTc-DPTA and a gamma camera. In normal subjects there was rapid movement of the radiopharmaceutical from the right colon to the rectum. In patients with severe idiopathic constipation, a spectrum of colonic abnormality was observed from slow transit involving the rectum and sigmoid only to slow transit involving the whole colon. The hepatic flexure to rectum transit time for the 'head of the isotope column' in normals ranged from 1-10 minutes (mean 5.3 minutes), whereas in patients the transit time was 14-25 minutes in four patients and radioisotope did not reach the rectum by two hours in three other patients (controls v patients, p less than 0.01). Patients also showed relatively impaired transport of the isotope 'mass'. This technique has shown that the normal colon is capable of rapid effective transport in response to a standard stimulus, and that patients with severe idiopathic constipation have a definable colonic motor disorder.     

Prospective,randomized trial comparing sigmoid vs. descending colonic J-pouch after total rectal excision

PURPOSE: The aim of this study was to compare the bowel function of sigmoid vs. descending colonic J-pouches after ultralow anterior resection for rectal cancer. METHODS: A prospective, randomized trial was conducted from March 1998 to September 1999. Ninety-two consecutive patients undergoing ultralow anterior resection for cancers arising from 3 to 10 cm from the anal verge were recruited. Forty-eight patients were males; the mean ages (standard error of the mean) for patients with sigmoid and descending colon pouches, respectively, were 65.2 (3.1) years and 62.3 (3.1) years. A total of 46 patients were randomly assigned to each group. Two patients from each group were excluded; abdominoperineal resection was performed for two patients in the sigmoid pouch group and one patient in the descending pouch group. One patient in the descending pouch group had a transanal resection of a benign polyp. Dukes staging and use of postoperative chemoradiotherapy were statistically similar in both groups. All patients underwent a standardized ultralow anterior resection. A defunctioning loop ileostomy was used routinely. Anorectal physiology and bowel function questionnaires were performed at six weeks after ileostomy closure and again at 6 and 12 months after surgery. RESULTS: Median follow-up was 12 (range, 7 to 25) and 12 (range, 6 to 25) months, respectively, for sigmoid and descending pouch groups. Median tumor and anastomotic heights, time to ileostomy closure, operative time, and postoperative stay were statistically similar in both groups. There were no significant differences in stool frequency, incontinence, urgency, use of pads and antidiarrheals, sensation of incomplete evacuation, and anorectal physiology results between groups (P > 0.05). CONCLUSION: Pouches made from sigmoid or descending colon give similar bowel function after ultralow anterior resection for rectal cancers.     

Electrical activity recorded from abdominal surface after gastrectomy or colectomy in humans

The visceral electrical activity recorded from the abdominal surface was studied before and after either total gastrectomy or colectomy. The patterns obtained from fast Fourier transform analysis demonstrated the disappearance of the power peak of approximately 3 cpm after gastrectomy, whereas colectomy did not result in the disappearance of the power peak of approximately 3 and 8-12 cpm. Only the frequencies of approximately 3.5-7.5 cpm were not present after colon surgery. These data demonstrate that the spectral power peaks at frequencies of approximately 3 cpm are entirely related to the stomach because they disappear after gastrectomy; the power peaks between 3.5 and 7.5 cpm are related to the colon because they are present after gastrectomy but not after colectomy; the power peaks between 7.5 and 11 cpm are related to the small intestine because they are present after either gastrectomy or colectomy. The authors conclude that the electrical activity recorded from the abdominal surface and analyzed by fast Fourier transform gives reliable information concerning the electrical activity of the stomach and small intestine, although it is less reliable concerning the electrical activity of the colon.     

Measuring colonic transit time in chronic idiophatic constipation.

INTRODUCTION AND OBJECTIVES: Colonic transit time can define three types of delay: right colon (colonic inertial), left colon and recto sigmoid. The aim of this study is to compare clinic characteristics and manometric results among the different groups with segmental colonic transit disorder. PATIENTS AND METHODS: 61 subjects were included in our study (5 men and 56 women) with and average age of 47.5 years (range: 17-84 years). We carried our a study of segmental and total colonic transit time, with the use of radio-opaque markers and sequential abdominal X-rays. We considered that transit time was prolonged when it was longer than 72 hours, and segmental transit time, when right colon was longer than 22 hours, left colon 37.2 hours and recto-sigmoid 37.2 hours. We included different clinic data: age, sex, place of residence stool frequency, abdominal pain, painful evacuation, incomplete evacuation, evacuation desire, dietary fibre intake, use of laxatives. We practised anorectal manometry in 20 patients. RESULTS: The average total colonic transit time was 38.2 hours in normal transit and 103 hours with disorder. The frequency in the three colonic segments, when there was a long total colonic transit time, was: 40% in the left colon, 33% in the recto-sigmoid and 27% in the right colon. We analysed the clinical characteristics of these three groups, finding more frequency of painful evacuation and defecation desire and lower dietary fibre intake in recto sigmoid. The most important abnormality in anorectal manometry was the hiposensitivity in the anorectal area, that only appeared in subjects with long segmental transit time in the right colon (colonic inertia), statistically significant. CONCLUSIONS: The measurement of colonic transit time with radio-opaque markers is a simple technique that allows for the objective detection of the different groups of patients with chronic idiopathic constipation. The exact typification of the abnormality is important for the individualization of each treatment.     

Increased segmental activity and intraluminal pressures in the sigmoid colon of patients with the irritable bowel syndrome.

Intraluminal pressure activity has been recorded in the unprepared true sigmoid colon of seven normal controls (mean age 37 years, range 22-55, three men) and seven patients with irritable bowel syndrome (IBS) (45 years, 24-75, four men) for 30 minutes before and 100 minutes after a standard 1000 kcal meal. Results differ from previously published data by showing much higher indices of pressure activity with amplitudes up to 490 mmHg in IBS, and 450 mmHg in controls. Study segment activity index and mean pressure wave amplitudes were significantly (p less than 0.015 and p less than 0.01) higher in IBS than controls, but per cent duration of activity was similar for the whole period of study. During the basal period in controls mean amplitudes recorded from the proximal sigmoid (40 cm from anus) were significantly (p less than 0.01) higher than those in the descending colon (50 cm), distal sigmoid (30 cm) and rectum (15 cm). This study shows that the increased colonic activity in IBS is characterised by increased amplitude, but not duration of pressure waves. In the basal state there is a high pressure zone in the proximal sigmoid colon of controls. Pressures in the unprepared colon of controls and IBS were higher than those measured under other experimental conditions.     

Treatment of malignant colonic obstructions with metal stents and laser

BACKGROUND/AIMS: The aim of this study was to evaluate the efficacy and safety of combined endoscopic therapy with self-expanding metallic endoprostheses and laser application in the management of malignant colonic obstruction. METHODOLOGY: Between March 1998 and September 2000, obstruction of the distal colon was diagnosed in a total of 11 patients (6 M, 5 F, age range: 67-87 years, mean: 73). The site of obstruction was located in the rectosigmoid colon (n = 6), in the sigmoid colon (n = 4) and in the descending colon (n = 1). The etiology of stenosis was colorectal adenocarcinoma (n = 8), ovarian cancer (n = 2) and infiltrating bladder carcinoma (n = 1). In all patients the tumor was considered non-resectable. Six patients had confirmed metastases, one refused colostomy and 4 were unable to undergo surgery. After radiological visualization of the proximal extent of the stricture, the stenosis was dilated with Savary-like (10 patients) and pneumatic balloon dilators (1 patient-descending colon). RESULTS: Stents were placed successfully in 10 patients. Prostheses migration distal to lesion, into the sigmoid colon, was observed in one patient (bladder cancer). A mild autoresolved bleeding was observed in 8 patients. Five patients remained free of clinical colonic obstruction until their death, which occurred 6-16 weeks (mean: 10) after stent placement. A moderate non-occlusive ingrowth of tumor into the stent lumen was documented in the other 5 cases. These patients were treated with introspective application of Diomed laser in a total of 16 sessions (4120-12,476 Joules each session, mean: 6258, power 10-14 W, interval between 2 sessions 6 weeks) and died of progressive disease without clinical signs and endoscopic findings of reobstruction 22-56 weeks (mean: 32) after stent placement. CONCLUSIONS: Metallic stent placement is an adequate palliative and cost-effective option, effective and save, in advanced colonic obstruction due to non-resectable tumors. It circumvents the need for colostomy and allows the patient a better quality of life. Delayed stent occlusion with tumor ingrowth requires a regular follow-up and can be treated with introspective laser ablation.