Pathogenesis of Crohn's disease.
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Adult↗
Biomedical subjects
M A Kamm
Publications and source records attributed to M A Kamm.
Drug management of ulcerative colitis.
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Adrenal Cortex Hormones↗
Colorectal and anal motility during defaecation.
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Anal Canal↗
Ileoanal pouch compliance and motor function.
Measurement of intrapouch pressure during continuous distension with water (pouchmetrography) was performed in ten patients with good pouch function after restorative proctocolectomy and a 'normal' baseline pressure curve was constructed from the mean pressures at 50-ml intervals. Eight other patients with poor pouch function were studied and the two groups were compared. Patients with poor function had significantly lower maximum tolerated volumes (297.5 versus 565 ml, P less than 0.02) and volumes which caused urgency (135 versus 265 ml, P less than 0.02). Baseline pressure curves were above the upper limit of the normal range (mean plus two standard deviations) for a substantial proportion of the recording in six of the patients with poor function. Large, isolated contraction waves were recorded in six of ten patients with good function and in three of those with poor function. Rhythmic waves were frequently seen in both groups but were more prominent in patients with poor function. Pouchmetrography is a provocative test of pouch motor function which may unmask abnormal muscle activity resulting from reduced compliance or a primary motility disorder.
Adult↗
Decreased sensitivity of muscarinic but not 5-hydroxytryptamine receptors of the internal anal sphincter in neurogenic faecal incontinence.
Previous studies of the internal anal sphincter in patients with neurogenic faecal incontinence have indicated an abnormality of the adrenergic innervation, but little is known about the responsiveness of other receptors in the internal and sphincter in this condition. In this study the in vitro sensitivity to carbachol and 5-hydroxytryptamine (5-HT) of muscle strips from patients with neurogenic incontinence (n = 6 and n = 7) and from control patients (n = 9 and n = 10) was examined. Preparations of internal and sphincter from patients with incontinence were less sensitive to the relaxant actions of carbachol than preparations from the control group. The pD2 value for carbachol (i.e. the negative logarithm of the concentration for half-maximal response) was significantly greater in the controls than in the incontinent group (mean(s.e.m.) 6.03(0.15) versus 5.43(0.24), P < 0.05). There was no significant difference in the contractile responses to 5-HT, which had pD2 values of 6.93(0.13) and 6.63(0.27) for the control and incontinent groups respectively. The unaffected state of the 5-HT receptor and the subsensitivity of the muscarinic receptor are discussed in relation to intrinsic neural control of the internal and sphincter in neurogenic faecal incontinence.
Adult↗
The small intestine and colon: scintigraphic quantitation of motility in health and disease.
Radioisotopes allow accurate quantitation of the pattern and effectiveness of the transit of chyme through the small and large intestines. Abnormalities of small bowel transit can be demonstrated in patients with the irritable bowel syndrome, and patients with chronic idiopathic intestinal pseudo-obstruction due to either a visceral myopathy or neuropathy. In the colon, radioisotopic studies of transit have demonstrated the site of delayed transit in some severely constipated patients. In patients with these disorders of transit, functional studies may influence the choice of medical or surgical therapy although there are few prospective studies which have established their worth in this context. Radioisotope studies can also be utilised to study the effectiveness of delivery of drugs to the small and large bowel, and to study the adequacy of rectal evacuation in patients with a defaecatory disturbance. The low radiation dose and possibility of frequent observations make radioisotope studies valuable for clinical and research studies in functional gastrointestinal disorders.
Colon↗
Observations on the characteristics of stimulated defaecation in severe idiopathic constipation.
A combined manometric and radioisotope study is described which was designed to investigate the motility characteristics of induced defaecation in the colon, rectum and anal canal, in patients with severe constipation. Five women with severe idiopathic constipation, aged 30-45 years, were studied. A multiple channel water-perfused manometric tube was placed colonoscopically into either the whole colon or left colon to monitor pressure activity. In two whole-colon studies, 5.5 MBq 111In DTPA and later 9 MBq 99mTc DTPA were instilled into the colon to monitor the transit of colonic contents in response to two separate stimuli. Motor activity was initiated on both occasions by intraluminal instillation of 5.5 mg bisacodyl. In the whole-colonic studies a right colonic stimulus initiated multiple high-pressure peristaltic waves which traversed the entire length of the colon. The bowel was then refractory to a second stimulus at the splenic flexure. In the five left colonic studies, a stimulus at the splenic flexure produced high-pressure peristaltic waves which proceeded distally, and which included a rise in rectal pressure. The anal canal relaxed simultaneously with the onset of peristalsis high in the left colon, and remained relaxed until the pressure wave reached the anus and bowel content had been expelled. In both types of study high-pressure waves corresponded to the effective transport of radioisotope. The constipated patients showed a coordinated motor response to the stimulus.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Results of stoma formation for idiopathic megarectum and megacolon.
Bowel resection for idiopathic megarectum and megacolon does not always predictably relieve symptoms and has a significant morbidity. We have therefore evaluated the results of stoma formation in this condition. All patients had a bowel frequency of less than one per week, and all had a dilated rectum or colon. Eight patients, six of who had had a previous unsuccessful operation for their constipation, had a colostomy--this relieved the constipation and the need for laxatives in all six patients with rectosigmoid dilatation, although one patient could not tolerate his stoma. Two patients with dilatation of the whole colon were not helped. An ileostomy was formed in four patients with previous colonic resection, with relief of constipation in all. However pain and abdominal distension were common persistent symptoms in both groups. Four patients with a colostomy and all four patients with an ileostomy felt subjectively improved with a stoma. Stoma formation is a viable alternative to more major surgery, either as a primary procedure or after previous surgery has failed.
Adolescent↗
The normal range and a simple diagram for recording whole gut transit time.
The time taken for radio-opaque markers to pass through the intestine has been measured in 25 healthy men, and 18 healthy women in both the follicular and luteal phases of the menstrual cycle. The subjects collected all stools after ingestion of the markers, the number of markers present in each stool was counted on a radiograph, and the number of markers retained in the body was thus determined for 12 hourly intervals after ingestion. The mean values (2 standard deviations) for men and women in both phases of the menstrual cycle proved to be so similar that the results have been combined to provide a single normal range. These data for the normal range for retained markers (as assessed by plain radiograph) are presented in diagrammatic form for clinical use. To assess whether a patient's whole gut transit time lies within the normal range a single type of marker can be used and an abdominal radiograph performed at 12 or 120 hours, the limits of the normal range. Normal subjects retain more than 20% of markers within 12 hours and less than 80% after 120 hours. If desired more information can be gained by giving different types of marker on successive days, so that several transit studies providing intermediate values can be obtained from a single abdominal radiograph at 120 hours.
Adolescent↗
The value of age of onset and rectal emptying in predicting the outcome of colectomy for severe idiopathic constipation.
We have evaluated the predictive value of pelvic floor dysfunction (as characterized by abnormal contraction during defaecation straining or absent balloon expulsion) and evacuation proctography on symptomatic severe idiopathic constipation after colectomy with ileorectal or colorectal anastomoses for improvement and the use of laxatives. We also determined whether there was a relationship between the age of onset of symptoms and the symptomatic outcome after surgery. Forty-four women (mean age 34 years) were studied. Twenty patients had had a preoperative evacuation proctogram. Of these, 8 evacuated completely and 12 incompletely. Of the 29 patients in whom puborectalis electromyography was performed, 19 had paradoxal contraction on straining. There was no statistical relationship between symptomatic outcome and complete or incomplete evacuation on proctography, the presence or absence of puborectalis paradox or the age of onset of constipation (before or after the age of 10 years). Twenty-five patients had a preoperative balloon expulsion test. Of these, 14 were not able to expel a 50 ml water-filled balloon, and all 14 (100%) still experienced postoperative pain; 8 (57%) were still using laxatives. Of the 11 patients who were able to expel a balloon, 6 (55%) experienced pain and 1 (11%) still required laxatives postoperatively. The differences in postoperative pain and laxative requirements between those unable and those able to expel the balloon were statistically significant. Thus the balloon expulsion test may have predictive value when considering colectomy in patients with severe idiopathic constipation.
Adolescent↗
An in vitro electrophysiological study of the colon from patients with idiopathic chronic constipation.
Preparations of the circular muscle layer from the sigmoid colon resected from patients with idiopathic chronic constipation were compared, at an electrophysiological level using the sucrose-gap technique, with preparations of the same region of the intestine resected from patients with rectal carcinoma. Non-adrenergic, non-cholinergic inhibitory neuromuscular transmission, represented by inhibitory junction potentials, was present in preparations from both groups. However, the inhibitory response in preparations from constipated patients had a slower or longer time-course than in those from cancer patients. Also, rebound activity following inhibitory transmission was observed in 34% of preparations from constipated patients but was observed in 67% of preparations from cancer patients. Preparations from both groups displayed the same patterns of spontaneous activity and the same proportion of each group was quiescent. The threshold for generation of action potentials and the passive resistance of the smooth muscle membrane were the same in both groups. However, quiescent preparations from constipated patients were less likely to discharge trains of action potentials when the smooth muscle membrane was depolarized than were preparations from cancer patients. These changes in transmission processes and excitability in tissue from constipated patients are discussed in relation to altered states of colonic motility found in people with idiopathic chronic constipation.
Adult↗
Partial colectomy and coloanal anastomosis for idiopathic megarectum and megacolon.
Adult patients with an idiopathic megarectum or megacolon can experience severe constipation requiring surgical treatment. Some of these patients have a proximal colon of normal diameter, with dilatation involving only the left or distal colon and rectum. The results of partial colonic and rectal resection with coloanal anastomosis in such patients have been reviewed. Seven patients (two female and five male) underwent a coloanal anastomosis over a seven-year period. The median age at operation was 19 years, the mean age at onset of symptoms was five years, and the mean follow-up period was one year. Five patients experienced a return to normal bowel frequency with the loss of most symptoms. One patient has an ileostomy because of persistent constipation after the procedure. One subject died because of postoperative bleeding from the anastomosis and subsequent cardiac and respiratory complications. This operation may have a place in the treatment of severe constipation caused by idiopathic megarectum and megacolon, but careful preoperative motility studies and meticulous attention to operative technique are required for a good outcome.
Adolescent↗
Abdominal rectopexy for complete prolapse: prospective study evaluating changes in symptoms and anorectal function.
The effect of abdominal rectopexy on bowel function is difficult to assess in retrospective studies because preoperative bowel habit cannot be determined accurately. This study examined bowel symptoms and physiologic tests of anorectal function prospectively in 23 patients before and at three months after rectopexy. Rectopexy eliminated complete prolapse in all and stopped bleeding in 16 of 18 patients. Incontinence improved significantly. Constipation (less than 3 bowel actions per week or straining for more than 25 percent of defecation time) was relieved in 4 of 11 affected patients but developed in 5 of the 12 who were not constipated preoperatively. Since the median bowel frequency was 21 motions per week before surgery and 17 afterward, the main determinant of constipation was straining. Abdominal pain was relieved after rectopexy in 6 of 12 patients but developed in 3 of 13 who were pain-free before surgery. Three patients (13 percent) had a first-degree relative with rectal prolapse. Perineal descent decreased significantly. Maximal anal resting pressure increased significantly, but this did not correlate significantly with improved continence. Twenty-one patients (91 percent) could expel a 50-ml balloon preoperatively; 18 of those 21 could still do so postoperatively. The two patients who could not expel the balloon preoperatively were able to do so postoperative. This study shows that rectal prolapse is associated with profoundly abnormal defecation and abdominal pain. While abdominal rectopexy improved continence, it may improve or worsen other bowel symptoms, including constipation.
Abdominal Pain↗
Peptide-containing neurons in different regions of the submucous plexus of human sigmoid colon.
Specimens of the sigmoid colon were obtained from male and female patients (n = 11) with carcinoma of the colon or rectum and studied immunohistochemically for vasoactive intestinal polypeptide-, somatostatin-, substance P-, neuropeptide Y-, calcitonin gene-related peptide-, met- and leu-enkephalin-, 5-hydroxytryptamine-, and dopamine beta-hydroxylase-containing nerves. In the subdivisions of the submucous plexus (namely, Schabadasch's, Meissner's, and the intermediate plexuses), substance P- and vasoactive intestinal polypeptide-immunoreactive nerve fibers were the most numerous, and equal densities of these nerves were found in all three layers. In contrast, few neuropeptide Y-, met-enkephalin-, leu-enkephalin-, calcitonin gene-related peptide-, somatostatin-, 5-hydroxytryptamine-, and dopamine beta-hydroxylase-immunoreactive nerves were found in these regions. The nerve cell bodies of the submucous plexus contained vasoactive intestinal polypeptide, substance P, leu-enkephalin, somatostatin, and 5-hydroxytryptamine but not neuropeptide Y, met-enkephalin, calcitonin gene-related peptide, and dopamine beta-hydroxylase. Vasoactive intestinal polypeptide-containing nerve cell bodies were found in all three subdivisions. Substance P-, leu-enkephalin-, and somatostatin-immunoreactive nerve cell bodies were found in Schabadasch's plexus and the intermediate region of the submucous plexus, but they were absent from Meissner's plexus; 5-hydroxytryptamine-containing nerve cell bodies were only observed in Schabadasch's plexus. The possible function of the neuropeptide-, dopamine beta-hydroxylase-, and 5-hydroxytryptamine-containing neurons in the different layers of the submucous plexus is discussed.
Adult↗
Intestinal pseudo-obstruction with deficient smooth muscle alpha-actin.
We describe a 48-year-old woman with chronic constipation since early childhood who has an intestinal myopathy associated with a hitherto undescribed absence by immunostaining of smooth muscle alpha-actin confined to the intestinal circular muscle. There were no abnormalities in other contractile proteins (myosin, tropomyosin, filamin, caldesmon or desmin) and despite the abnormality of a contractile protein isoform in the circular muscle, no significant morphological changes were identified by light microscopy or ultrastructural examination. A possible developmental mechanism for the observed change is proposed. The use of specific antibodies to isoforms of contractile proteins may have potential value in the study of intestinal myopathies.
Actins↗
Idiopathic constipation: any movement?
Severe constipation now attracts considerable research interest. As a consequence, there have been recent advances in most aspects of this disorder. The epidemiology of this condition is now better appreciated, and subgroups of patients with different epidemiologies, symptom complexes, aetiologies, and treatments can now be distinguished. Radioisotopes enable detailed transit studies to be obtained of the entire gastrointestinal tract. Careful psychologic evaluation is an essential part of the evaluation. In young women with severe idiopathic constipation there is a decrease in propulsive mass movements, and specific colonic neurotransmitter abnormalities have been identified. Biofeedback therapy is an effective treatment for many of these patients. The variable results of surgery are now also clearly defined. Patients with chronic idiopathic intestinal pseudoobstruction can be categorized on the basis of their pathologic findings; detailed tissue studies may be required. The recognition that severe constipation encompasses various different conditions is leading to a more precise understanding of pathogenesis and treatment.
Constipation↗
Anal endosonography in the investigation of faecal incontinence.
Forty-four consecutive patients with incontinence of solid stool of traumatic or idiopathic aetiology were examined by anal endosonography and standard anorectal physiology tests. Anal endosonography showed an external anal sphincter defect in four out of 11 (36 per cent) patients with idiopathic (neurogenic) incontinence. In the remaining seven patients both parts of the sphincter were intact and a linear relationship was found between the resting anal canal pressure and the endosonographic thickness of the internal anal sphincter. Twenty-eight out of 33 (85 per cent) patients with incontinence of traumatic origin had external sphincter defects, confirmed by concentric needle electromyogram mapping in the 19 patients in whom this was performed. Eleven of these 28 (39 per cent) patients also had disruption of the internal sphincter. Anal endosonography has revealed significant abnormalities in patients with faecal incontinence and has a complementary role to anorectal physiology in the routine investigation of these patients.
Adolescent↗