Injectable silicone biomaterial (PTQ) is more effective than carbon-coated beads (Durasphere) in treating passive faecal incontinence--a randomized trial.

OBJECTIVE: Both injectable silicone biomaterial (PTQ) and pyrolytic carbon-coated beads (Durasphere) have been shown to be effective in treating passive faecal incontinence due to internal sphincter dysfunction. This is a randomized study to evaluate their relative safety and efficacy. METHOD: Forty patients (mean age 59.5 years vs 58.9 years) were randomized to have inter-sphincteric injection of PTQ or submucosal injection of Durasphere. Patients were assessed with anorectal physiology, endoanal ultrasound, a validated incontinence score and quality of life questionnaires. RESULTS: In the Durasphere group, complications included rectal pain (5%), erosion through rectal mucosa (10%), and type III hypersensitivity reaction (5%). No complications occurred in the PTQ group. Compared with PTQ, Durasphere group has a more rapid action, with improved continence at 2 weeks after injection. In both groups, faecal continence significantly improved 6 weeks after injection, and continued to improve significantly up to 6 months in both groups (P < 0.0001). At 6 weeks, 6 and 12 months after injection, significantly more PTQ patients achieved greater than 50% improvement in Wexner's continence score than Durasphere patients (respectively, P = 0.01; P < 0.0001; P = 0.001). There was a significant improvement in faecal incontinence quality of life scale and the 12-month physical health scale of Short Form-12 health survey in the PTQ group but not in the Durasphere group. CONCLUSION: In patients with internal sphincter dysfunction, injectable silicone biomaterial was safer and more effective than Durasphere.

Predictive factors for faecal incontinence after third or fourth degree obstetric tears: a clinico-physiologic study.

OBJECTIVE: This is a prospective study to review the natural history of anorectal dysfunction after primary repair for third or fourth degree obstetric tear and to identify the predictive factors for significant faecal incontinence. METHOD: From January 2003 to December 2005, 121 consecutive women (mean age 29.9 +/- 4.7) who sustained third or fourth degree obstetric tears were assessed. All had primary repair by obstetricians. They were assessed using anorectal physiology testing and endoanal ultrasound. Short-term (3-month postpartum) and medium-term (mean 18.8 +/- 7.7 months) Wexner's continence scores were obtained. RESULTS: Among the 121 women, seven were excluded because of incomplete follow-up. At short-term assessment, 25 out of 114 women were incontinent. One of them underwent another sphincter repair for significant faecal incontinence. Twenty-one and three patients respectively, had mild (Wexner's score 1-4) and moderate (Wexner's score 5-8) symptoms. At medium-term assessment, 24 patients remained incontinent; of these, 20 had mild symptoms (Wexner's score 1-4) and four had moderate incontinence (Wexner's score 5-8). The parity (P = 0.04), degree of obstetric tear (P = 0.036) and short-term Wexner's scores at 3 months postpartum (P < 0.0001) were significantly related to the change in Wexner's scores at medium-term assessment. However, the short-term Wexner's score was the only identifiable predictive factor for significant faecal incontinence. CONCLUSION: Most women suffering from third or fourth degree obstetric tear were continent or mildly incontinent. Poor Wexner's score at short-term assessment at 3 months postpartum was predictive of faecal incontinence in the medium-term.

Prospective, case-matched study of heated and humidified carbon dioxide insufflation in laparoscopic colorectal surgery.

PURPOSE: Laparoscopic colorectal surgery is often prolonged and may cause hypothermia. It is uncertain if heated and humidified carbon dioxide (CO(2)) in laparoscopic colorectal surgery is beneficial. This is a prospective case-matched study on the use of heated and humidified CO(2) in patients undergoing laparoscopic colorectal surgery. METHOD: Twenty consecutive patients undergoing laparoscopic colorectal surgery with heated (36 degrees C) and humidified (95%) CO(2) were compared with 20 consecutive patients using standard CO(2) (30.2 degrees C). All procedures were performed by a single surgeon in an institution. The changes in core temperature during surgery, visual quality of images and the short-term clinical outcome were documented. RESULTS: The core temperature fell during surgery in both groups. Although the fall of core temperature was more in the control group, it was not statistically significant (P > 0.05). The passage of flatus was more delayed in heated and humidified group (P = 0.004), but it did not affect the hospital discharge. All the other parameters, including the quality of visual images and the postoperative pain, were similar in both groups. CONCLUSIONS: Despite better temperature maintenance (nonsignificant), pneumoperitoneum using heated and humidified CO(2) gas did not appear to have any clinical benefits in laparoscopic colorectal surgery.

Rectogesic (glyceryl trinitrate 0.2%) ointment relieves symptoms of haemorrhoids associated with high resting anal canal pressures.

OBJECTIVE: Some haemorrhoids are associated with high resting anal canal pressures. The aim of this study was to assess if Rectogesic, a topical glyceryl trinitrate 0.2% ointment was effective in relieving symptoms of early grade haemorrhoids associated with high resting anal canal pressures. METHOD: This was a prospective, two-centre, open label study of 58 patients with persistent haemorrhoidal symptoms. Patients with first or second degree haemorrhoids and a maximum resting anal canal pressure > 70 mmHg were included. Rectogesic was applied three times a day for 14 days. Anorectal manometry was performed 30 min after the first application of Rectogesic. A 28-day diary was completed during 14 days of therapy and for 14 days after cessation of treatment. This recorded the incidence of rectal bleeding, and visual analogue scales for anal pain, throbbing, pruritus, irritation and difficulty in bowel movement. RESULTS: Maximum resting anal canal pressures were reduced after application of Rectogesic (115.0 +/- 40.4 mmHg vs 94.7 +/- 34.1 mmHg, P < 0.001). In the study period and at 14 days after cessation of Rectogesic, there was significant reduction in rectal bleeding (P = 0.0002), and significant improvement of anal pain (P = 0.0024), throbbing (P = 0.0355), pruritus (P = 0.0043), irritation (P = 0.0000) and difficulty in bowel movement (P = 0.001). The main adverse event was headache in 43.1% of patients. CONCLUSION: Rectogesic is a safe and feasible treatment for patients with early grade haemorrhoids associated with high resting anal canal pressures.

Laparoscopic surgery for ulcerative colitis - a meta-analysis.

OBJECTIVE: To assess the safety and feasibility of laparoscopic surgery for patients with ulcerative colitis. METHODS: A search of published studies in English between January 1992 and September 2005 was obtained, using the MEDLINE and PubMed databases and the Cochrane Central Register of Controlled Trials. Two independent assessors reviewed the studies using a standardized protocol. Where raw data, means and standard deviations were available, meta-analysis was performed using the Forest plot review. Studies where medians and ranges were presented were separately analysed. RESULTS: The duration of surgery for laparoscopic and open procedures were similar (weighted mean difference 62.92 min, P = 0.19). Patients were able to tolerate oral intake significantly earlier, with a weighted mean difference of 1.39 days (P = 0.002), but recovery of bowel function was similar (weighted mean difference 0.73 days, P = 0.36). The length of hospital stay was shorter for patients who had undergone laparoscopic surgery, with a weighted mean difference of 2.64 days (P = 0.003). The complication rate was higher in open colectomy, compared to laparoscopic colectomy (67.6%vs 39.7%, P = 0.005). For restorative proctocolectomy, complication rates were comparable between the laparoscopic and open groups (P = 0.25). CONCLUSIONS: The time taken to perform laparoscopic surgery is similar to open surgery. Patients are able to tolerate oral intake earlier, and have a shorter hospitalization. Laparoscopic colectomy was safer compared to the open procedure, but both were equally safe for patients who had restorative proctocolectomy. Thus, laparoscopic surgery for ulcerative colitis is both safe and feasible.

Systematic review on the short-term outcome of laparoscopic resection for colon and rectosigmoid cancer.

OBJECTIVE: Several large randomized controlled trials on laparoscopic resection for colon and rectosigmoid cancer have recently been published. There is a need to provide an up-to-date systematic review in this subject. METHODS: A literature search of all published randomized trials in English between January 1991 and September 2005 was obtained, from Ovid MEDLINE, EMBASE, CINAHL, and All EBM Reviews (Cochrane Central Register of Controlled Trial, Cochrane Database of Systemic Review, and Database of Abstracts of Reviews of Effects), including e-links to the related articles. Two independent assessors reviewed the trials using a standardized protocol. Where means and standard deviations were available, meta-analysis was performed using the Forest plot review. Studies where medians and ranges were presented were separately analysed. RESULTS: A total of 17 randomized controlled trials with 4013 procedures were reviewed. The conversion rate varied widely between studies and was lowest in single-Centre trials. There were no significant differences in overall and surgical complication rate, anastomotic leak rate, re-operation rate and oncological clearance. However, laparoscopic resection has a significantly lower peri-operative mortality (odds ratio 0.33; P = 0.005), lower wound complications (odds ratio 0.65; P = 0.01), less blood loss (weighted mean difference 0.11 l; P < 0.00001) and reduced postoperative pain scores by 12.6% with reduction of requirements for narcotic analgesia by 30.7%. After laparoscopic surgery, patients passed flatus 38.8% earlier (weighted mean difference 27.6 h; P < 0.00001) and had bowel movement 21.0% earlier (weighted mean difference 23.9 h; P < 0.00001) and resumed oral diet 28.3% sooner than patients in the open group (weighted mean difference 27.3 h; P < 0.00001). Patients were discharged 19.1% earlier after laparoscopic surgery than open surgery (weighted mean difference 1.7 days; P < 0.00001). Laparoscopic resection took 28.7% longer (weighted mean difference 40.1 min; P < 0.00001) to perform. CONCLUSIONS: Laparoscopic resection for colon and rectosigmoid cancer is feasible, safe and has many short-term benefits.

Which is the optimal bowel preparation for colonoscopy - a meta-analysis.

OBJECTIVE: To assess which bowel preparation agent is most effective. METHODS: A search of randomized trials between January 1990 and July 2005 was obtained, using MEDLINE and PubMed databases, and the Cochrane Central Register of Controlled Trials. Meta-analysis was performed using the Forest plot review. RESULTS: Sodium phosphate (NaP) was more effective in bowel cleansing than polyethylene glycol (PEG) - odds ratio 0.75 (95%CI: 0.65-0.88; P = 0.0004); and sodium picosulphate (SPS) - odds ratio 0.52 (95%CI: 0.34-0.81; P = 0.004). PEG and SPS were comparable in bowel cleansing ability, odds ratio 1.69 (95%CI: 0.92-3.13; P = 0.09). NaP was more easily completed by patients compared to PEG, odds ratio 0.16 (95%CI: 0.09-0.29; P < 0.00001). More patients were able to complete SPS than PEG, but this was not statistically significant - odds ratio 0.56 (95%CI: 0.28-1.13; P = 0.11). NaP and PEG were comparable in terms of adverse events, odds ratio 0.98 (95%CI: 0.82-1.17; P = 0.81), although NaP resulted in more asymptomatic hypokalaemia and hyperphosphataemia. NaP and SPS appeared to have similar incidence of adverse events. PEG resulted in more adverse events than SPS, odds ratio 3.82 (95%CI: 1.60-9.15; P = 0.003). CONCLUSIONS: NaP was more effective in bowel cleansing than PEG or SPS and was comparable in terms of adverse events. Patients have more difficulty completing PEG than NaP and SPS. Biochemical changes associated with a small-volume preparation like NaP, albeit largely asymptomatic, mandate caution in patients with cardiovascular or renal impairment.

Injectable silicone biomaterial for fecal incontinence caused by internal anal sphincter dysfunction is effective.

PURPOSE: Fecal incontinence caused by a weak or disrupted internal anal sphincter is common but there has been no effective treatment. This prospective study evaluates the medium-term clinical effects of an injectable silicone biomaterial, PTP (Bioplastique), used to augment the internal anal sphincter. METHOD: Eighty-two patients (64 females; median age, 66 years) with severe fecal incontinence and a low anal resting pressure caused by internal anal sphincter dysfunction (defect, n = 11; intact, n = 71) were randomized to PTP injection into intersphincteric space and internal anal sphincter with (Group A, n = 42) or without (Group B, n = 40) guidance by endoanal ultrasound. Both groups were similar in terms of age, gender, past anorectal surgery, duration of follow-up (median, 6 months; range, 1-12 months), and baseline continence score. Sixty-two percent of Group A and 55 percent of Group B had prolonged pudendal nerve terminal motor latency. RESULTS: There was no significant complication. Two patients in Group A and four patients in Group B noted minor discomfort at injection sites. At one month postprocedure, endoanal ultrasound confirmed retention of silicone biomaterial without migration. In both groups, fecal continence was significantly improved by PTP implants 1 month after injection, but continued to improve significantly for up to 12 months in Group A and 6 months in Group B (P < 0.001). Improvement in fecal continence and maximum anal resting pressure was significantly greater in Group A, in whom injection was guided by endoanal ultrasound, than in Group B. At three months after injection, significantly more Group A patients than Group B patients achieved >50 percent improvement in Wexner's continence score (69 percent vs. 40 percent; P = 0.014). Ninety-three percent of Group A and 92 percent of Group B had >50 percent improvement in global quality of life scores (visual analog scale). At a median follow-up of 6 months, all domains of the fecal incontinence quality of life scale improved significantly in both groups; however, the physical function and mental health scores of Short Form-12 only improved in Group A. A prolonged pudendal nerve terminal motor latency had no effect on functional outcome in either group. CONCLUSION: Injection of silicone biomaterial provided a marked improvement in fecal continence and quality of life in patients with internal sphincter dysfunction, despite the presence of pudendal neuropathy.

Direct repair vs. overlapping sphincter repair: a randomized, controlled trial.

PURPOSE: The aim of this study was to compare the results of two surgical techniques (direct end-to-end vs. overlapping) of delayed repair of a localized anterior defect of external anal sphincter after an obstetric trauma. METHODS: During a five-year period, 23 patients were randomly assigned to direct end-to-end repair (n = 12) or overlapping sphincter repair (n = 11), using 2-0 PDS sutures. Two patients from each group had an internal anal sphincter defect that also was repaired. All patients had a normal pudendal nerve terminal motor latency preoperatively. Evaluations included endoanal ultrasound, anorectal manometry, and neurophysiologic evaluation. Continence was assessed by the Cleveland Clinic Continence Score (0-20; 0, perfect continence; 20, complete incontinence). RESULTS: The two groups were comparable with regard to age (median, 45 years), past history of sphincter repair (n = 2), and posterior vaginal repair. There was no major morbidity. The wound-healing rate was identical between the two groups. However, of the patients undergoing overlapping repair, two had fecal impaction, and one had a urinary retention. Median preoperative continence score was 17 in both the direct-repair group (score, 8-20) and the overlap group (score, 7-20). At a median follow-up of 18 months, the improvement in continence was similar between the two surgical groups, with a median continence score of 3, respectively. In both surgical groups there was a significant and similar improvement in maximum squeeze pressure and in the functional anal canal length postoperatively (P < 0.05), but the mean resting pressure was relatively unchanged. In the overlap group, one patient developed a unilaterally prolonged pudendal nerve terminal motor latency that was persistent 22 months after surgery, and two patients had impaired fecal evacuation postoperatively. CONCLUSIONS: This randomized, controlled study suggests that the outcome is similar whether direct end-to-end or overlapping repair of a sphincter defect is performed. Overlapping repair might be associated with more difficulties with fecal evacuation and a prolonged pudendal nerve terminal motor latency postoperatively.

Practical issues in adjuvant therapy for rectal cancer.

INTRODUCTION: While the standard adjuvant therapy for rectal cancer includes radiation therapy (RT) and chemotherapy (CT), the optimal treatment combination and sequencing have yet to be determined. In recent years, a large number of clinical trials have been reported in this rapidly evolving field. MATERIALS AND METHODS: A review of pivotal trials in rectal cancer was undertaken with a focus on the important recent literature that has determined the current approach to adjuvant treatment. RESULTS: Multiple well-conducted, randomised studies have demonstrated that, for patients with stage II and III rectal cancer, the combination of adjuvant CT and RT reduces the risk of local recurrence (LR) and distant recurrence, improves overall survival and should form part of the standard treatment. Due to the reduced risk of LR, the absolute benefit from adjuvant RT is less if optimal oncologic surgery has been performed. Theoretical advantages and preliminary clinical results suggest that delivering part of the adjuvant therapy preoperatively will produce superior results. Ongoing randomised trials will define the relative merits of long-course RT (with CT) and short-course RT alone as preoperative therapy. Preoperative combined modality therapy might increase the rate of sphincter preservation, although definitive data supporting this is still being awaited, whereas RT alone does not facilitate sphincter preservation. CONCLUSION: Management of patients with rectal cancer is complex and requires ongoing close collaboration between the colorectal surgeon, medical oncologist and radiation therapist in order to achieve the best possible outcomes. The optimal combination of CT and RT will be defined by current clinical trials.

Argon plasma coagulation is an effective treatment for refractory hemorrhagic radiation proctitis.

INTRODUCTION: Chronic radiation proctitis complicating pelvic radiotherapy can be debilitating. It commonly presents with rectal bleeding, which can be difficult to control. Medical management of hemorrhagic radiation proctitis is not very successful, although surgery carries high risks. Thus, endoscopic treatments are preferred. The aim of this study is to assess the efficacy of argon plasma coagulation applied endoscopically to treat hemorrhagic radiation proctitis that has been refractory to topical formalin therapy. METHODS: Twelve patients who had ongoing bleeding from radiation proctitis, after previously failed formalin therapy, underwent endoscopic treatment using argon plasma coagulation. The efficacy of treatment was assessed by grading the frequency and severity of bleeding (0-4, 0 being no bleeding), hemoglobin level, and transfusion requirements. RESULTS: At a median follow-up of 11 months, ten patients (83 percent) had a significant reduction in the severity and frequency of bleeding, with complete cessation in six (50 percent). The presence of coexistent radiation-induced sigmoiditis in two patients was associated with reduced but persistent bleeding, because of difficulty in targeting the bleeding sites in the sigmoid colon. The median number of treatment sessions per patient was two (range, 1-3), with the number of sessions correlated with the extent of the proctitis. All patients had an improvement in their hemoglobin level, with the mean increasing from 11.2 to 12.3 g/dl. In the six months before starting therapy, all patients had been taking iron supplements, and four had required blood transfusions (median 3 units, range, 2-6). Iron supplements were ceased four weeks after the completion of therapy in all cases, and no further transfusions were required during the study period. None of the patients experienced any significant side effects or complications. CONCLUSIONS: Argon plasma coagulation is an effective and safe treatment for hemorrhagic radiation proctitis that has been refractory to topical formalin therapy.

Local excision of rectal cancer: what is the evidence?

PURPOSE: Although local excision of rectal cancers is a less morbid alternative to radical resection, its role as a curative procedure is unclear. The role of adjuvant therapy after local excision is also controversial. This review aims to examine current evidence on local excision of rectal cancers and how it fits into the management algorithm for rectal cancer. METHODS: A literature review was undertaken through the MEDLINE database and by cross-referencing previous publications, thus identifying 41 studies on curative local excision of rectal cancer published in English. Details of preoperative staging, surgical procedures, adjuvant therapy, follow-up, and outcome measures, including complications, survival data, recurrences, and salvage were examined. RESULTS: Preoperative staging of rectal cancers is variable. Digital rectal examination and computerized tomography are used in most studies. Endorectal ultrasound is used in some patients in 9 of 41 studies. Local excision preserves anorectal function, and seems to have limited morbidity (0-22 percent). Local excision alone is associated with local recurrences in 9.7 (range, 0-24) percent of T1, 25 (range, 0-67) percent of T2 and 38 (range, 0-100) percent of T3 cancers. The addition of adjuvant chemoradiotherapy after local excision yields local recurrence rates of 9.5 (range, 0-50) percent for T1, 13.6 (range, 0-24) percent for T2, and 13.8 (range, 0-50) percent for T3 cancers. Data on local excision after preoperative chemoradiotherapy for tumor down staging are limited. Factors other than T-stage that lead to higher local recurrence rates after local excision include poor histologic grade, the presence of lymphovascular invasion, and positive margins. Local recurrences after local excision can be surgically salvaged (84 of 114 patients in 15 studies), with a disease-free survival rates between 40 and 100 percent at a follow-up of 0.1 to 13.5 years. CONCLUSIONS: Local excision for rectal cancers is associated with a low morbidity and provides satisfactory local control and disease-free survival rates for T1 rectal cancers. There is, however, a need for a randomized, controlled trial for T2 cancers, comparing local excision with adjuvant chemoradiotherapy to radical resection.

Phase II clinical trial of preoperative combined chemoradiation for T3 and T4 resectable rectal cancer: preliminary results.

PURPOSE: Although preoperative chemoradiation for high-risk rectal cancer may improve survival and local recurrence rate, its adverse effects are not well defined. This prospective study evaluated the use of preoperative chemoradiation for T3 and T4 resectable rectal cancer, with special emphasis on treatment morbidity, pathologic remission rate, quality of life, and anorectal function. METHODS: Forty-two patients (30 men, 12 women) were enrolled in the study. Median distance of the distal tumor margin from the anal verge was 6.5 cm. Preoperative staging was based on digital rectal examination, endorectal ultrasound, and computed tomography. None of the patients had distant metastases. All patients had 45 Gy (1.8 Gy/day in 25 fractions) over five weeks, plus 5-fluorouracil (350 mg/m(2)/day) and leucovorin (20 mg/m(2)/day) bolus on days 1 to 5 and 29 to 33. Quality of life was assessed with the European Organization for Research and Treatment of Cancer 30-item quality-of-life questionnaire (QLQ-C30) and its colorectal cancer-specific module (QLQ-CR38) questionnaires. Objective anorectal function was assessed by anorectal manometry and pudendal nerve terminal motor latency. Surgery was performed 46 (range, 24-63) days after completion of adjuvant therapy. RESULTS: Nineteen patients (45 percent) had Grade 3 or 4 chemoradiation-induced toxic reactions. Four patients developed intercurrent distant metastases or intraperitoneal carcinomatosis at completion of chemoradiation. Thirty-eight patients underwent surgical resection: abdominoperineal resection, anterior resection, and Hartmann's procedure were performed in 55 percent, 39 percent (11 of 15 patients had a diverting stoma), and 5 percent, respectively. Major surgical complications occurred in 7 patients (18 percent) and included anastomotic leak (n = 1), pelvic abscess (n = 1), small-bowel obstruction (n = 3), and wound breakdown (n = 2). Final pathology was Stage 0 (no residual disease), I, II, and III in 6 (16 percent), 7 (18 percent), 9 (24 percent), and 16 (42 percent) patients, respectively. There was a deterioration, after chemoradiation and surgery, in the quality of life on all subscales assessed, with physical, role, and social function being most severely affected. The symptoms most adversely affected were micturition, defecation, and gastrointestinal problems. Body image and sexual enjoyment deteriorated in both men and women. Chemoradiation alone led to prolonged pudendal nerve terminal motor latency in 57 percent of 7 patients assessed. CONCLUSION: Preliminary results have identified defined costs with preoperative chemoradiation, which included treatment-induced toxicity, a high stoma rate, and adverse effects on quality of life and anorectal function.

Faecal incontinence after lateral internal sphincterotomy is often associated with coexisting occult sphincter defects: a study using endoanal ultrasonography.

BACKGROUND: Troublesome faecal incontinence following a lateral internal sphincterotomy (LIS) is often attributed to faulty surgical techniques: division of excessive amount of internal sphincter or inadvertent injury to the external sphincter. The aim of the present paper was to assess the anatomic and physiological factors that may contribute to faecal incontinence following a technically satisfactory lateral internal sphincterotomy by a group of colorectal specialists. METHODS: Fourteen patients (nine women, five men; median age: 38 years; range: 23-52 years) who developed troublesome postoperative faecal incontinence were evaluated by clinical assessment, endoanal ultrasonography and anorectal physiological studies (manometry, pudendal nerve terminal motor latency) by two independent observers. The Cleveland Clinic continence score (0-20; 0, perfect continence; 20, complete incontinence) was used to quantify the severity of faecal incontinence. Fourteen continent subjects after a LIS (nine female patients, five male patients; median age: 36 years; range: 20-44 years) were also evaluated as 'continent' controls (continence score

Dietary fiber and colorectal neoplasia.

PURPOSE: Dietary fiber has been implicated in colorectal neoplasia, despite conflicting evidence. This is a review of the currently available data on the role of dietary fiber in colorectal carcinogenesis. METHODS: A literature search was conducted using the MEDLINE database. All case-control, longitudinal, and randomized, controlled studies published in English between 1988 and 2000 were identified, as were animal model studies in the period 1986 to 2000. Data from the various studies were tabulated and systematically analyzed, with particular emphasis on the effect of dietary fiber on tumor incidence and luminal parameters such as short chain fatty acids. RESULTS: Epidemiologic correlation studies show a high intake of dietary fiber to be associated with a lower risk of colorectal neoplasia. Thirteen of the 24 case-control studies reviewed demonstrated a protective effect of dietary fiber against colorectal neoplasia, and 16 showed a protective effect of vegetables or vegetable fiber. On the other hand, of 13 longitudinal studies in various cohorts, only 3 demonstrated a protective effect of fiber and 4 a protective effect of vegetables or vegetable fiber. The five published randomized, controlled trials all investigated the effect of increased fiber intake on short-term adenoma recurrence; however, none showed any significant protective effect. Among 19 experimental studies in animal models, 15 showed a protective effect of fiber against tumor induction compared with controls. Animal studies also showed that poorly fermentable fibers (e.g., wheat bran and cellulose) were more protective than soluble fibers (e.g., guar gum and oat bran), which sometimes enhanced carcinogenesis. No clear correlation was found between luminal pH or short chain fatty acids and tumor induction. CONCLUSIONS: On the basis of current data, there is little evidence to support the use of dietary fiber supplements to reduce the risk of colorectal neoplasia. Lifelong and early exposure may be important but are difficult to study. Other risk factors interact with the effects of dietary fiber.

Chronic radiation proctitis.

BACKGROUND: Increasing use of radiation therapy in pelvic malignancy has led to an increase in the incidence of chronic radiation proctitis. The commonest presenting complaint is rectal bleeding. METHODS: A comprehensive MEDLINE search was undertaken for all articles relating to radiation proctitis. RESULTS: The natural history of the disease is poorly documented but improvement is likely in milder forms, with persistence of symptoms in more severe forms. The pathological manifestations of the disease are summarized with particular comparison to acute radiation proctitis. The common clinical presentations and the principles of assessing patients with radiation-induced proctitis will be reviewed. The present article also reviews current treatment options, with particular reference to newer endoscopic therapies and surgical principles of management. CONCLUSIONS: The initial therapy for problematic rectal bleeding related to radiation-induced proctitis shoud be endoscopic therapy with argon plasma coagulation or topical formalin therapy. Surgery is reserved as a last resort for resistant rectal bleeding and for complicated radiation-induced strictures and fistulas.