Rectosigmoid Area Research Articles

Diagnostic accuracy of double-contrast enema and rectosigmoidoscopy in connection with faecal occult blood testing for the detection of rectosigmoid neoplasms.

Four hundred and fifty-eight consecutive subjects with a positive faecal guaiac test when screened for early detection of colorectal neoplasms were investigated with double-contrast enemas and rectosigmoidoscopy (60 cm). The results of these two methods were compared. The radiologists and endoscopists were unaware of the result of each others' examination at the time of their own investigation. Altogether ten subjects with carcinoma in the rectosigmoid area were found. The radiologists and endoscopists each overlooked four of these ten carcinomas and only four of the carcinomas were diagnosed with both methods. Fifty-six of one hundred and seven adenomas were 1 cm or larger in diameter and located in the rectum or the sigmoid colon. Thirteen of the fifty-six adenomas were missed by double contrast enema and ten by endoscopy and only thirty-three adenomas were diagnosed with both methods. Neoplasms in the rectum and the sigmoid colon are sometimes difficult to diagnose with both radiology and endoscopy. Rectosigmoidoscopy (60 cm) should therefore be used as a complement to double contrast enemas if this method is chosen for investigation of a patient with rectal bleeding.

Neurotensin increases colonic motility

The effects of neurotensin on colonic motility were investigated in 6 healthy volunteers (rectosigmoid area) and 7 patients (ascending colon and at the splenic flexure). Neurotensin (12 pmol/kg · min) infused intravenously for 30 min increased the duration of the contractions to 76% in the ascending colon and 46% in the rectosigmoid area. In the postinfusion period, the values were 42% and 67%, respectively. The motor activity did not change significantly at the splenic flexure. During the infusion period, the motility index increased from 870 to 4500 in the ascending colon and from 332 to 1700 in the rectosigmoid area. In the rectosigmoid area, however, a statistically significant increase was recorded first after cessation of the infusion. All subjects reported increased sensation of intestinal movement after intravenous infusion of neurotensin, and the patients discharged a median volume of 600 ml of bowel contents 20 min after cessation of the infusion. The data show that neurotensin causes an increase in colonic motility in the ascending colon of patients and also, after a latent period, in the rectosigmoid area of healthy subjects.

Distribution and spread of colonic lesions in shigellosis: a colonoscopic study.

In a study of the distribution and severity of colonic lesions in patients with shigellosis, colonoscopy was performed for 33 men with this disease. All 33 patients had inflammatory lesions in the rectosigmoid area; in 18 (55%) the lesions extended to the splenic flexure, in 14 (42%) the disease extended to the distal transverse colon, in nine (27%) the area of involvement included the proximal transverse colon, and in five (15%) pancolitis was evident. In most patients lesions were continuous and diffuse, with the intensity of inflammation decreasing in a proximal direction. Biopsied samples from proximal lesions usually showed less severe inflammation than did those from more distal lesions. Aphthoid erosions, which have not previously been described in shigellosis, were observed in five patients. Proximal colitis was associated with diarrhea of four or more days' duration (P less than .01, Fisher's exact test). These findings indicate that the rectosigmoid is the most frequently and most severely affected area of the colon in shigellosis and suggest that during the course of shigella infection, colonic lesions extend in a proximal direction.

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Our previous lectin-binding study of the human colorectal mucosa revealed that, in the distal large bowel, Ulex europaeus agglutinin-L (UEA-l) binding was detectable in adenocarcinomas and adenomas, whereas it usually was not found in the normal epithelium. The aim of the present study was to obtain further information about the chemical nature of the constituents of the epithelium in polyposis coli and solitary colorectal adenoma. UEA-l binding to demonstrate alpha-L-fucosyl residue-containing glycoproteins was conducted on entire colon specimens from 4 patients with polyposis coli and on polypectomy specimens from 23 patients with solitary adenomas of the sigmoid colon and rectum with the use of a highly sensitive lectin-antilectin immunoperoxidase method. In the rectosigmoid area of all 4 patients with polyposis coli, positive UEA-l staining was observed not only in the adenomatous epithelium but also in the nonneoplastic epithelium intervening between the polyps. In contrast, in 18 of 23 patients with solitary adenomas, positive UEA-l staining was observed only in the adenomatous epithelium but not in the adjacent nonneoplastic epithelium. In the remaining 5 solitary adenomas, UEA-l staining was shown neither in the adenomatous epithelium nor in the adjacent nonneoplastic epithelium.

Rectosigmoid perforation and intestinal evisceration from transanal suction

Transanal suction injuries were sustained in 1981 by five children when they sat upon uncovered swimming area drain sites. Tears of the rectosigmoid areas occurred in each with associated evisceration and loss of substantial amounts of small intestine because of mesenteric separation. These cases are reviewed.

Human large intestinal epithelium: Light microscopy, histochemistry, and ultrastructure

Despite numerous reports of morphologic characteristics of premalignant and malignant large intestinal epithelium, the literature lacks comprehensive reports of the morphologic features of the epithelium of the normal large intestine, except of the rectum. Large intestinal epithelium from 41 persons was obtained, and samples from the ascending, transverse, descending, and rectosigmoid areas were studied by light microscopy, histochemical techniques, and transmission and scanning electron microscopy. The morphologic features and histochemical reactions of the various segments of the large intestine are different. Neutral mucopolysaccharide is predominant in the ascending colon, whereas the rectum has predominantly or exclusively acidic mucin. Only three basic epithelial cell phenotypes have been identified: undifferentiated cells, mucous cells, and endocrine cells. The columnar cells at the surface between the crypts appear to be a variant of mucous cells. Compared with other segments, the rectum shows an unusually high concentration of endocrine cells, positively correlating with the high incidence of carcinoid tumors in that segment of the large intestine. The mucous cells in all segments contain large mucous vacuoles and small apical vesicles. The apical vesicles show variable electron density, being most dense in the ascending colon and becoming progressively less dense at the transverse and descending colon and most electron-lucent in the sigmoid colon and rectum. Ultrastructurally, the mucin shows a variable degree of heterogeneity in the proximal segments. This study suggests that some of the previously described ultrastructural features of abnormal large-intestinal epithelium may be only the result of failure to compare the so-called abnormal cells with normal cells from the same region. Well-controlled studies of the abnormal epithelium of a particular segment of large intestine must include the normal epithelium from the identical segment as control in order to make interpretations accurate.

Distribution of Blood Group Substances in Normal Human Colon. Use of the Unlabeled Antibody (PAP) Immunoperoxidase Technic to Identify A and B Blood Group Substances

A modification of the unlabeled antibody immunoperoxidase technic, using human antisera to identify blood group substances A and B in normal human colon is described. Overall, staining for the blood group substances is strongest in the cecum and proximal colon; there is a progressive reduction of staining for the blood group substances in the distal colon with almost complete loss in the recto-sigmoid area. The blood group substances are present in epithelial cells and in epithelial mucin, the most intense positive staining often being located in the supranuclear, Golgi region of the cells.

Diminutive polyps: histopathology, spatial distribution, and clinical significance

This retrospective study of 329 diminutive colon polyps revealed that 49.2% of the polyps were neoplastic, whereas 49.9% were nonneoplastic. 36.8% of the polyps were metaplastic, and 0.9% had mixed metaplastic and adenomatous components. The metaplastic polyps had a predominance in the distal portion of the large bowel, with 76.9% being located distal from the splenic flexure and 52.9% being located in the rectosigmoid area. Neoplastic polyps were distributed throughout the colon, with 65.4% located from the splenic flexure distally and 34.5% located proximal to the splenic flexure. These findings suggest that a much larger proportion of diminutive polyps are neoplastic and therefore at risk to progress to carcinoma than previously considered.

Distribution of blood group substances in normal human colon. Use of the unlabeled antibody (PAP) immunoperoxidase technic to identify A and B blood group substances.

A modification of the unlabeled antibody immunoperoxidase technic, using human antisera to identify blood group substances A and B in normal human colon is described. Overall, staining for the blood group substances is strongest in the cecum and proximal colon; there is a progressive reduction of staining for the blood group substances in the distal colon with almost complete loss in the recto-sigmoid area. The blood group substances are present in epithelial cells and in epithelial mucin, the most intense positive staining often being located in the supranuclear, Golgi region of the cells.

Segmental colonic transit time.

Mean segmental transit time of radiopaque markers through the right colon, left colon and rectosigmoid areas of adults and children has been calculated form their distribution on consecutive plain films of the abdomen. Overall mean transit does not differ significantly in the large bowel between adults and children. However, there are regional differences within the colon in relation to age. Mean transit time in the right colon is 13.8 hours in adults and 7.7 in children (p less than 0.01). Corresponding values in the left colon are 14.1 and 8.7 hours (p less than 0.02) and, in the rectum, 11 and 12.4 hours (p = NS). The percentage of the mean total large bowel transit time spent in the right colon, left colon and rectosigmoid area are respectively for adults and children 33 +/- 4 and 28 +/- 3 per cent (p = NS); 39 +/- 4 and 32 +/- 4 per cent (p = NS); and 28 +/- 4 and 41 +/- 4 per cent (p less than 0.05), indicating a relative stagnation in the rectosigmoid area of children. These physiologic differences may have implications in diseased states.

The irritable bowel syndrome. A clinical review and ethical considerations.

The irritable bowel syndrome (IBS) is clinically characterized by a wide variety of symptoms, including dyspepsia, flatulence, nausea, cramping abdominal pain, constipation and/or diarrhea, and nonspecific symptoms, probably reflecting autonomic nervous system overreactivity. Physiologically, the colonic motor abnormality is characterized by an altered slow-wave rhythm, quantitative differences from normal in the repetitive contraction pattern of the rectosigmoid area, and increased colonic muscle responsiveness to hormones such as cholecystokinin and pentagastrin. The diagnosis of IBS involves practical and ethical considerations as well as the need for decisive reassurance of the patient through judicious examination. Treatment of IBS requires a thoughtful and sensitive approach to the patient, recognition of IBS as an important clinical problem, regularization of bowel function, relief of the abdominal discomfort, and intelligent emotional support.

Irritable bowel syndrome.

Patients with different irritable bowel symptoms and normal subjects were compared to determine whether subtypes of irritable bowel syndrome (IBS) could be distinguished on the basis of colonic motility or psychological test scores. A provocative test involving stepwise distension of the rectosigmoid area revealed two types of colonic motility. Slow contractions having durations of at least 15 sec and occurring at irregular intervals were more frequent in IBS patients than in normals but did not differentiate constipation from diarrhea. Fast contractions having durations of less than 15 sec and occurring in runs at frequencies of 6–9 cpm were more frequent in patients with diarrhea than in normals or constipated IBS patients. Constipated patients showed no more fast contractions than normals. Severity of bowel symptoms was correlated with the overall amount of motility (motility index) in patients with diarrhea but not in patients with constipation. Patients with IBS showed significantly elevated levels on the following psychological traits: anxiety, interpersonal sensitivity, depression, hostility, and somatization of affect. However, there were no significant trait differences between patients with diarrhea and those with constipation. Also, there was no correlation between amount of psychopathology and either colonic motility or severity of symptoms in the whole group of IBS patients.

Ileus caused by Endometriosis in the Rectosigmoid Area

Ileus caused by Endometriosis in the Rectosigmoid Area

Use of pressure release valve to prevent colonic injury during colonoscopy

Although bowel perforation during colonoscopy is often related to direct endoscopic pressure or injury in the rectosigmoid area, colonic perforation has been also reported with overinflation of air. This latter type of rupture appears related to formation of a blind loop, to an overly competent ileocecal valve that prohibits colonic decompression, or to use of particular power sources that generate unsafe pressure levels. In an effort to obviate this pneumatic type of rupture, the authors tested a pressure release valve developed by the Olympus Corporation that supplants the standard air-water valve in available Olympus colonoscopes. Use of this valve revealed a significant difference in mean and maximal intracolonic pressures generated during colonoscopy. Moreover, its use resulted in a marked decrease in tissue damage in the pneumatically inflated cadaver colon. Incorporation of such a pressure release valve into available colonoscopes should reduce the risk of pneumatic colon rupture and improve the safety of diagnostic colonoscopy.

Irritable bowel syndrome: physiological and psychological differences between diarrhea-predominant and constipation-predominant patients.

Patients with different irritable bowel symptoms and normal subjects were compared to determine whether subtypes of irritable bowel syndrome (IBS) could be distinguished on the basis of colonic motility or psychological test scores. A provocative test involving stepwise distension of the rectosigmoid area revealed two types of colonic motility. Slow contractions having durations of at least 15 sec and occurring at irregular intervals were more frequent in IBS patients than in normals but did not differentiate constipation from diarrhea. Fast contractions having durations of less than 15 sec and occurring in runs at frequencies of 6-9 cpm were more frequent in patients with diarrhea than in normals or constipated IBS patients. Constipated patients showed no more fast contractions than normals. Severity of bowel symptoms was correlated with the overall amount of motility (motility index) in patients with diarrhea but not in patients with constipation. Patients with IBS showed significantly elevated levels on the following psychological traits: anxiety, interpersonal sensitivity, depression, hostility, and somatization of affect. However, there were no significant trait differences between patients with diarrhea and those with constipation. Also, there was no correlationbetween amount of psychopathology and either colonic motility or severity of symptoms in the whole group of IBS patients.

Antibiotic associated pseudomembranous colitis with negative proctosigmoidoscopy examination

Most investigators have stressed that the diagnosis of antibiotic associated pseudomembranous colitis is made by proctosigmoidoscopic examination. In our investigation, 6 patients with tissue culture evidence of a clostridial toxin in stools and either normal or only edematous rectal mucosa were studied with total colonoscopy. Five of six patients demonstrated pseudomembranes located in various areas of the colon at a time when the rectosigmoid area was uninvolved. This demonstrates the occurrence of antibiotic associated pseudomembranous colitis which can be missed by routine proctosigmoidoscopy. The incidence of rectal sparing in this disease remains undetermined. Further investigation to determine the occurrence of antibiotic colitis, response to different treatments, or sensitivity of tissue culture assays as a diagnostic aid in antibiotic associated pseudomembranous colitis must take this subgroup into account.

COLORECTAL CANCER A STUDY OF 230 PATIENTS

Clinical presentation, risk factors, investigations, pathology and treatment were examined in a retrospective review of 230 patients with colorectal cancer. Many patients presented with symptoms not usually associated with colorectal cancer, such as pain in the upper part of the abdomen, and rectal bleeding separate from the stool. Iron deficiency anaemia was an uncommon presentation. Over all, one-third of patients had at least one risk factor for colorectal cancer. Risk factors such as adenomatous polyps and family history of colorectal cancer were more common than inflammatory bowel disease and polyposis coli. Although a delay in diagnosis was recorded in one-quarter of patients, the finding of a negative correlation between duration of symptoms and extent of spread suggests that the length of the symptomatic illness is not an important factor in prognosis. Contrary to surgical and medical teaching, only 43% of cancers were in the rectum and rectosigmoid area, and, hence, within reach of the standard sigmoidoscope. Surgical resection was performed in 76% of patients. Forty-three per cent of patients who underwent surgery developed at least one postoperative complication resulting in a longer stay in hospital.

The Subpopulations of Circulating White Blood Cells in Inflammatory Bowel Disease

A detailed analysis of the species of lymphocytes was carried out in 58 patients with inflammatory bowel disease (IBD). These individuals were further divided into 31 with Crohn's disease (CD) and 27 with ulcerative colitis (UC). There were 13 CD patients with only small bowel involvement called "regional enteritis" and 18 who had some degree of colonic involvement called "ileocolitis". Similarly, the UC group was subdivided into 9 patients with disease confined to the rectosigmoid area called "proctosigmoiditis" and 18 with more extensive involvement called "universal colitis". We also studied 13 patients who had undergone previous colectomy and ileostomy and 78 healthy age- and sex-matched controls. Although there was no increase in the absolute number of lymphocytes in patients with ileocolitis and universal colitis, the percentage of these cells was decreased because of an increase in both polymorphonuclear leukocytes and monocytes. In IBD and its subgroups, mean T lymphocytes, determined by the sheep red blood cell rosette technique, were not significantly different from the controls either in percentage or absolute number. Furthermore, no difference was noted between UC and CD. However, there seems to be a subpopulation of patients with UC or CD whose T cells are reduced below 1 SD of the mean. There was also no difference in the number of immunoglobulin-bearing B cells in both diseases; however, when the B cells were enumerated by their ability to rosette with antibody-complement-coated sheep cells (EAC), we found a marked decrease in percentage (P less than 0.001) and absolute number (P less than 0.0005) relative to the control population. The decrease bore a direct relation to the severity of the disease process and, although more marked in patients with UC, was present in CD also.

Colonic Myoelectric Activity in the Irritable Bowel Syndrome

Although the irritable bowel syndrome has been characterized as an abnormality in colonic motor activity occurring in response to certain stimuli, the etiology of this abnormality is unclear. The purpose of this study was to compare colonic myoelectric and motor activity in normal subjects and in patients with the irritable bowel syndrome. Myoelectric activity was recorded using a bipolar electrode clipped to the mucosa of the rectal and rectosigmoid areas. Basic electrical rhythm (BER), spike potential activity, and intraluminal pressure were recorded in both groups. Two types of BER were observed. The major component of the BER had a frequency of approximately 6 cycles per min, whereas the minor component had a frequency of approximately 3 cycles per min. Although both types of BER were recorded in the two groups, thitable bowel syndrome. The 3 cycles per min activity was present as 44.1 +/- 1.3% of the total BER in the irritable bowel syndrome, as compared with 10.0 +/- 1.6% in the normal group (P less than 0.001). Basal spike potential and motor activity were similiar in both groups. Because it had been demonstrated previously that colonic responsiveness to certain stimuli was increased during the slower frequency BER, it is suggested that the abnormalities in colonic motor response reported in the irritable bowel syndrome may be related to this difference in colonic BER.

Crohn's disease of the colon. Analysis of the diagnostic value of radiology, endoscopy, and histology.

Radiologic, endoscopic, and histologic features were analyzed in 15 patients with Crohn's disease of the colon. Radiologic findings were considered of diagnostic value in only 6 (40%), characteristic endoscopic lesions were found in 13 (87%) and diagnostic histologic features in 11 (73%). Endoscopy combined with biopsy was diagnostic in all 15 cases. The extent of involvement of endoscopy frequently disagreed with the radiologic assessment, particularly in the rectosigmoid area. Studies in 8 patients indicate that sigmoidoscopy and coloscopy with multiple biopsies provide an accurate alternative to radiology to estimate the extent and severity of the lesions and their evolution during corticosteroid and/or azathioprine treatment.