Ileoanal Reservoir Research Articles

P655 The ileorectal anastomosis after a total colectomy is a feasible and valid surgical alternative in the treatment of inflammatory bowel disease

Abstract Background Colectomy is still necessary in some patients with inflammatory bowel disease (IBD). The decision of the technique for the restoration of the bowel continuity depends on the characteristics of the patient and whether it is Crohn’s disease (CD) or ulcerative colitis (UC). The options for the reconstruction are proctectomy with an ileoanal reservoir or an ileorectal anastomosis (IRa). The aim of this study is to evaluate the need of a proctectomy with a definitive ileostomy after an ileorectal anastomosis, the associated risk factors and the need for advanced therapies. Methods This retrospective study includes patients with colectomy and IRa from the ENEIDA national registry. Medical treatment offered during the postoperative follow up and the need for a proctectomy and a definitive ileostomy were evaluated according to the type of IBD. Results Of the 394 patients who underwent an IR, 37% had UC and 63% CD with a medium age of 58 years (RIQ 48-68) and a median follow-up after the IR of 174 months (RIQ 70- 266). 17% of UC’s patients and 42% of CD’s patients had associated perianal disease (p<0.001). The cumulative probability for a definitive ileostomy in UC’s patients was 1%, 2%, and 6% at 5, 10 and 20 years respectively and 1%, 3%, and 11% at 5, 10 and 20 years respectively for the CD (p=0.035). Postoperative maintenance treatment with biologicals was left in 45% (44% UC and 47% CD; p=0.28). During follow-up, the probability of starting biological treatment was 8%, 17%, 35% at 2, 5 and 10 years in CD and 3%, 12%, 28% at 2, 5 and 10 years in UC (p=0.59). Conclusion The probability of requiring a definitive ileostomy/proctectomy after an IR is low, although is more frequent in patients with CD than with UC. Because of this low probability an IR is a valid alternative to the reservoir or even to the proctectomy with a definitive ileostomy in selected patients, keeping in mind one third of the patients would need advanced therapies.

Bile acid dysmetabolism in inflammatory bowel diseases

Aim: To summarize the state-of-the-art data on the molecular mechanisms of bile acid (BA) synthesis and absorption, their impaired absorption and receptor-dependent signaling, as well as on the effects of the gut microbiota on BA metabolism in inflammatory bowel diseases (IBD).
 Key messages: BA malabsorption is one of the relevant mechanisms in the development of diarrhea in IBD. It may occur due to various disorders of the ileum, such as terminal ileitis, ileocolitis or ileocecal resection in Crohn's disease and ileoanal reservoir in ulcerative colitis. Molecular mechanisms of BA malabsorption in IBD are related to a defect in the BA uptake by the apical sodium dependent bile acid transporter (ASBT), as well as to a decrease in the expression of pregnane X receptor (PXR) and farnesoid X receptor (FXR), whose activation by glucocorticoids results in an increase in the BA reabsorption in the ileum and a decrease in hologenic diarrhea. The metabolic profile of luminal BA in IBD is characterized by an increased content of conjugated and 3-OH-sulfated BA and reduced levels of secondary BA. The decrease in the relative abundance of the Lachnospiraceae and Oscillospiraceae spp. in IBD patients leads to a decrease in the efficiency of microbial biotransformation of BA. Changes in the BA metabolic profile in IBD affect the gut microbiota, and impaired interaction with the FXR, PXR, G protein-coupled bile acid receptor (GPBAR1), retinoid-related orphan receptors (RORs) and vitamin D receptor (VDR) results in a pro-inflammatory response and increased intestinal permeability, bacterial translocation, and IBD progression. BA metabolism in IBD-associated primary sclerosing cholangitis (PSC-IBD) is characterized by a significant decrease in the luminal BA pool, and the microbiota composition is remarkable for an increase in the relative abundance of Fusobacterium and Ruminococcus spp., and a decrease in Veillonella, Dorea, Blautia, Lachnospira and Roseburia.
 Conclusion: Disordered synergistic interplay of BA with intestinal microbiota results in disruption of the ligand-receptor interaction and BA metabolic transformation, which contributes to the activation of the immune system, formation of a vicious circle of chronic inflammation and IBD progression. Further studies into mutual influence of the gut microbiota, BA metabolism and receptor signaling may promote the development of new methods for the diagnosis and treatment of IBD.

Standardization of ileoanal J-pouch surgery technique: Quality assessment of minimally invasive ileoanal J-pouch surgery videos

BackgroundIleal pouch anal anastomosis is a complex procedure associated with significant morbidity, with several complications after ileal pouch anal anastomosis surgery leading to pouch failure. The aim of the study is to evaluate the heterogeneity surrounding the technique of ileoanal J-pouch surgery by assessing the safety and quality of published online peer-reviewed surgical videos. MethodsIleal pouch anal anastomosis videos published on peer-reviewed surgical journals and video channels were edited and anonymized to demonstrate specific steps of the surgical procedure: mobilization and division of the rectum, formation of the ileoanal J-pouch reservoir, anastomosis, and lengthening techniques. The anonymized videos were presented to a group of reviewers with expertise in ileal pouch anal anastomosis blinded to the names and affiliations of the surgeons performing the procedure. Primary outcome was the rate of interobserver variability in the assessment of specific technical steps of the ileal pouch anal anastomosis surgery procedure. Secondary outcome was the appropriateness of the use of surgical videos review as an assessment tool for ileal pouch anal anastomosis surgery, measured as rate of reviewers being unable to answer for poor video quality. ResultsIn total, 29 video fragments were distributed, and 13 assessors completed a 60-item survey, organized in 7 major domains. The survey completion rate was 93.4%. Out of a total 729 answers, in 23 (3.2%) the reviewers indicated they were unable to comment due to poor video image, and in 48 (6.5%) were unable to comment due to the particular step not being shown in the procedure. The proportion of assessors rating rectal mobilization technically appropriate ranged from 30.7% to 92.3% and from 7.7% to 69.2% for safety. The level of rectal division was considered appropriate in 0 to 53.8% of the videos, whereas the stapling technique used for rectal division was appropriate in 0 to 70% of the videos. ConclusionOur study assessed published peer-reviewed videos on ileal pouch anal anastomosis surgery and reported heterogeneity in the safety of the demonstrated techniques. Blind assessment of published peer-reviewed ileal pouch anal anastomosis videos reported a high rate of unsafe or inappropriate technique for rectal mobilization and transection in the reviewed videos, with fair interobserver agreement among reviewers. There is a need for consensus on what is considered safe and appropriate in ileal pouch anal anastomosis surgery. Peer review of ileal pouch anal anastomosis surgery videos could facilitate training and accreditation in this complex procedure.

EP.TU.911Analysis of the outcomes following reversal of loop ileostomy

Abstract Aims A defunctioning loop ileostomy is constructed to reduce the incidence and the consequences of anastomotic leaks following sphincter-sparing colorectal resection. Its construction and reversal may be associated with complications. The aim of this study is to present a snapshot of the outcome of reversal of loop ileostomy in a teaching general hospital. Methods All patients whose loop ileostomy was reversed in 2018 were studied. Sociodemographic and clinical data were collected. The outcomes measured were length of hospital stay, return of bowel function, morbidity and mortality. Results Nine patients had reversal of ileostomy by experienced colorectal surgeons during this period. The patients, 5 males and 4 females, had a median age of 58 years (range 20 to 77 years). The main indications for construction of a loop ileostomy were low anterior resection for rectal neoplasia (7 patients) and iatrogenic rectal perforation during hysterectomy (1 patient), and total colectomy with ileoanal pouch reservoir for ulcerative colitis (1 patient). The ileostomies were reversed between 5 to 10 months following the main operations. The postoperative stay was between 2 to 12 days. The complications included one anastomotic leak, requiring immediate re-operation, 3 wound infections and 2 incisional hernias. There were no postoperative deaths. Conclusion In this study our overall complication rate was well within the range reported in the literature, with only one patient requiring immediate re-operation. The presence of a senior colorectal surgeon at operation as well as careful attention to detail is key to keeping complications to a minimum.

Crohn's disease of the ileoanal pouch

Crohn's disease of the ileoanal pouch is a known albeit infrequent outcome of restorative proctocolectomy with ileoanal reservoir for inflammatory bowel disease colitides. Although an adverse outcome, many patients will benefit from a combined medical-surgical multidisciplinary approach to pouch retention. In this review article, we will discuss inflammatory disorders of the body of the pouch and the rectal cuff which lay on a spectrum, including pouchitis, cuffitis and Crohn's disease of the ileoanal pouch. It is imperative that readers fully understand conditions on both sides of the spectrum as treatments often overlap and it is necessary to undergo many of the mentioned treatments, or at least consider them, before undergoing what can be complex, re-operative abdominopelvic surgery with permanent re-diversion with the pouch left in situ, pouch excision or rarely pouch revision. We will also discuss outcomes of intentional ileoanal pouch for isolated Crohn's colitis.

P286 Rate of colectomy in ulcerative colitis: Results from a Spanish cohort with 15 years of follow-up

Abstract Background Knowing the natural history of ulcerative colitis (UC) is essential to understand the evolution of the disease, assess the impact of different therapeutic strategies, identify poor prognostic factors and provide patients with understandable information who help them in decision making. It has been suggested that biological drugs could modify natural history of UC and therefore decrease the rates of colectomy. In Spain, infliximab is approved for CU since 2005. Methods We performed a retrospective study that includes all patients with a definitive diagnosis (DD) of UC or Unclassifiable Colitis (UC) in the Navarra Incident Cohort (which includes all patients diagnosed between 2001 and 2003 in Navarra, Spain). Our objectives were to analyse the Colectomy Incidence Rate (CIR) from diagnosis to the end of follow-up (12-31-2017) and identify predictive factors of colectomy. Results We included 174 patients with DD of UC (42.5% E2 - 26.8% E3) and 5 of IC: 44.1 women, median age 39.2 years (7–88), median follow-up of 15.7 years. At the end of the follow-up, 8 patients underwent colectomy (CIR 3 surgeries per 100000patients-year). Timing of colectomy was: 3 at the initial diagnosis (<1 month), 2 in the first 2 years, 2 at 5 years and 1 at 12 years from diagnosis. All had previously received steroids, 5 immunomodulators and 2 biological agents. In 7 (87%) the surgery was urgent and the indication, megacolon in 3 (37.5%), severe outbreak in 3 (37.5%) and failure to medical treatment in 2 (25%). In 5 cases (62.5%), an ileoanal reservoir was made and in 3 definitive ileostomy. Conclusion In our cohort, global colectomy rates are lower than those reported in other series and occur mostly in the first 5 years of evolution.

Anti-tumour necrosis factor agents in Crohn's disease and ulcerative colitis: Beyond luminal disease

Anti-tumor necrosis factor agents (anti-TNF) drugs are commonly used in patients with inflammatory bowel disease (IBD) and have proven effective in both induction and maintenance therapy in luminal Crohn's disease and ulcerative colitis. Their efficacy has also been proven in fistulising perianal Crohn's disease. However, the evidence in other scenarios, such as stricturing, penetrating and non-fistulising perianal Crohn's disease, extraintestinal IBD manifestations and ileoanal reservoir complications, is not as robust. The aim of this review was to perform an analysis of the available literature and to determine the role of anti-TNF drugs in common clinical practice in patients affected by these complications.

Agentes anti-factor de necrosis tumoral en enfermedad de Crohn y colitis ulcerosa: más allá de la enfermedad luminal

Anti-tumor necrosis factor agents (anti-TNF) drugs are commonly used in patients with inflammatory bowel disease (IBD) and have proven effective in both induction and maintenance therapy in luminal Crohn's disease and ulcerative colitis. Their efficacy has also been proven in fistulising perianal Crohn's disease. However, the evidence in other scenarios, such as stricturing, penetrating and non-fistulising perianal Crohn's disease, extraintestinal IBD manifestations and ileoanal reservoir complications, is not as robust. The aim of this review was to perform an analysis of the available literature and to determine the role of anti-TNF drugs in common clinical practice in patients affected by these complications.

Stapled Ileoanal Reservoir for Restorative Ileal Pouch Anal Anastomosis

Stapled Ileoanal Reservoir for Restorative Ileal Pouch Anal Anastomosis

Test Taking

Test Taking

Inflammatory bowel disease in the obese patient.

Obesity is becoming increasingly more common among patients with inflammatory bowel disease. In this review, we will explore the epidemiological trends of inflammatory bowel disease, the complex interplay between the proinflammatory state of obesity and inflammatory bowel disease, outcomes of surgery for inflammatory bowel disease in obese as compared with non-obese patients, and technical concerns pertaining to restorative proctocolectomy and ileoanal pouch reservoir, stoma creation and laparoscopic surgery for inflammatory bowel disease in obese patients.

Colorectal Congress in St. Gallen, Switzerland

December. Snow. Frozen trees. Cars slowly proceeding in the darkness like metal ghosts. This is what I found arriving to St. Gallen, 1 h from Zurich, where Professor Jochen Lange had organized the fourth European Colorectal Congress, helped by his staff including the charming and skilled Judith Balzien. This outstanding Meeting has become a ‘‘must’’ in the field, hosting the best specialists in the field for 3 days and being attended by over 1,200 people from all countries, mostly Europe, but also United States and Japan. Complications and Liver metastases were the topics of the St. Gallen European Colorectal Congress 2010. ‘‘What do volume and learning curves tell us?’’, ‘‘Which are the preventable causes of failure during colorectal cancer surgery?’’, P. Quirke, R.J. Heald, and H. Kehlet tried to reply to these questions. L. Pahlman discussed on the bowel preparation in colorectal surgery and E. Rullier reported his experience on risk factors for anastomotic leakage after resection for rectal cancer, whereas R. Madoff, the Editor of DCR, explained how to treat postoperative leakages and abscesses. Again, N. Mortensen reported on the Oxford experience on anastomotic leaks stating that his complication has become very rare, but there was disagreement in the audience, W.A. Bemelman reported on Endo-Sponge treatment for anastomotic leakage. T. Holm, from Sweden, talked about the ‘‘Anterior Resection Syndrome’’ which may affect many patients with fecal incontinence and urgency, especially after long course preoperative radiotherapy, and may be treated with sacral neuromodulation and bulking agents’ injection, and possibly prevented constructing a J-pouch above the anastomosis. N.S. Williams and V.W. Fazio reported their experience on parastomal hernias and coloanal anastomosis, whereas the Spanish Dutch M.A. Cuesta impressed the audience saying that one out of 200 patients dies following a diverting ileostomy closure after anterior resection for rectal cancer. The chairman, S.D. Wexner, asked the audience how many would routinely ‘‘protect’’ a very low anastomosis: almost everybody raised his hand. The author of the present report gave a talk on postoperative complications after PPH and STARR, including rectal perforations following stapled hemorrhoidopexy, and chronic proctalgia after stapled rectal resection. The chairman A. Herold recommended more selective indications to surgery in case of obstructed defecation. R. J. Nicholls reported the St. Mark’s experience with ileo-anal reservoir and ‘‘re-do’’ pouch, whereas S.D. Wexner stressed the need for an adequate prevention of postoperative adhesions, a major cause of morbidity and expenses. ‘‘Seprafilm’’ might be the right answer, provided that it does not increase the risk of suture dehiscences. A Consultant Corner, brilliantly chaired by H. Abcarian, the Iranian–U.S. surgeon, ended the complications session. ‘‘Portal vein embolisation’’, ‘‘Surgical options in patients with peritoneal seeding’’, ‘‘Stereotactic body radiation’’, ‘‘Radio-frequency ablation’’, and ‘‘Regional chemotherapy’’ were some of the topics of the session Liver metastases, presented by M.A. Choti, P.H. Sugarbaker, A. Mendez Romero, N.E. Kemeny, and E.K. Abdalea. A number of Satellyte Symposia were also organized, among them the one on the VAAFT, the video-assisted The congress sessions are also available online at the following address: www.docAcademy.ch.

Functional Outcome After Restorative Proctocolectomy in Pigs: Comparing a Novel Transverse Ileal Pouch to the J-Pouch and Straight Ileoanal Anastomosis

BackgroundRestorative proctocolectomy followed by an ileoanal J-pouch procedure is the therapy of choice for patients with familial adenomatous polyposis and ulcerative colitis. After low anterior rectal resection, the authors have reported on a novel, less complex pouch configuration, a transverse coloplasty pouch. The aim of the present work was to apply this new design to the ileal pouch construction, to evaluate feasibility, and to measure functional results in comparison with the J-pouch and the straight ileoanal anastomosis using the pig as an animal model. MethodsTwenty-three pigs underwent restorative proctocolectomy followed by reconstruction with straight ileoanal anastomosis (IAA; n = 5), J-pouch (n = 7), and a transverse ileal pouch (TIP; n = 11). Pigs were followed for 6 days postoperatively. Peristaltic function was assessed by manometry proximal to the pouch, in the reservoir, and at the level of the ileoanal anastomosis. Functional outcome was monitored by semiquantitative assessment of the general condition of the animals, postoperative feeding habits, and stool frequency and consistency. A Fourier analysis was performed in order to compare peristalsis in the ileal reservoirs. The reservoir volume was measured in situ by triple contrast computed tomography scan with 3D reconstruction. ResultsSeventeen animals survived for 1 week. There was no difference in the general condition or the feeding habits of the groups. A significant number of pigs with the TIP pouch (7/10) had semisolid or formed stools as opposed to liquid stools after J-pouch (6/6) and IAA (4/5; p = 0.01). TIP animals had a lower stool frequency (3.2±1.14 per day) on day 6 after the operation than pigs with J-pouch, 5.33 ± 1,03, and IAA, 4.6±1.82 (p = 0.0036). The in situ volume of the pouches did not differ significantly. The Fourier analysis demonstrated a disruption of peristalsis by the J-pouch and the TIP reconstruction but not after IAA. ConclusionThe function of ileoanal reservoirs after proctocolectomy may result from the disruption of properistaltic waves after pouch formation. The mechanism of peristalsis disruption is independent of the in situ volume of the pouch.

Kontinente Stuhlreservoire – eine chirurgische Herausforderung

The optimization of surgical techniques has made it possible to now treat patients with deep-seated rectal cancer by performing deep anterior rectal resection with coloanal anastomosis while avoiding a permanent stoma. To prevent a high bowel movement frequency and limited continence with an imperative need to empty the bowel, the coloanal pouch operation was developed to construct a rectal substitute. Nowadays, patients with ulcerative colitis or familial adenomatous polyposis of the colon undergo proctocolectomy as the definitive treatment for their underlying disease. Continuity is restored by creating an ileoanal reservoir. This contribution describes the surgical indications and pathophysiological changes for the colon J-pouch and ileoanal reservoir. In addition, explanations of the surgical techniques for both procedures are presented. The functional results are compared with those of other reconstruction options and discussed, taking our own results into consideration.

Clinical and functional results after restorative proctocolectomy.

Of 84 patients who underwent restorative proctocolectomy with an ileoanal reservoir in 21 Italian departments of surgery, 51 had ulcerative colitis, 32 familial polyposis and 1 intractable constipation. Follow-up information is available for all 58 patients who had their ileostomy closed, the length of follow-up ranging between 2 and 78 months. There were no operative deaths. A failure rate (i.e. excision of the pouch) of 3 per cent was observed. Sepsis was the most common postoperative complication, and was most often related to ileoanal anastomosis dehiscence (15 per cent), followed by small-bowel obstruction requiring laparotomy (10 per cent). Clinical 'pouchitis' occurred in 14 per cent of patients after ileostomy closure. The average frequency of defaecation was four motions per 24 h; evacuation was spontaneous in all patients and only 5 per cent complained of troublesome faecal soiling while 34 per cent had occasional incontinence to flatus and mucus. Patients with a short or absent rectal cuff had a lower rate of incontinence (30 versus 48 per cent, difference not statistically significant) without any increase in the frequency of genito-urinary disorders. None of the two most used reservoirs, the J (n = 40) and S pouch (n = 17) showed significant superiority in terms of bowel frequency and continence. Incontinence was more likely in patients whose ileostomy closure had been delayed for more than one year.

Parks of the Parks Ileo-anal Reservoir

Sir Alan Guyatt Parks (1920–1982) received his undergraduate education at Brasenose College, Oxford, then with benefit of a Rockefeller scholarship completed his medical training at the Johns Hopkins University in the US and later at Guy’s Hospital in London where his principal research centered on the anatomy of the anal canal. In 1978, as consultant surgeon to the St. Mark’s Hospital and in collaboration with R. J. Nichols, he devised a sphincter-saving ileo-anal anastomosis and reservoir adapted to the surgical management of ulcerative colitis.

Restorative proctocolectomy with ileo-anal reservoir, a histopathological, histochemical, and electron microscopic study

This study was conducted to investigate the nature of colonic metaplasia in ileo-anal pouches and incidence / frequency of pouchitis in the same. Biopsy specimens from 8 patients with functioning ileal pouches were studied using routine histology, mucin histochemistry and electron microscopy, over a 2 - year period. All 8 patients had villous abnormalities in the form of blunting of villi and sub total or partial villous atrophy. 6 patients had an increase in the goblet cell population and Paneth cell hyperplasia. These changes were supported by electron microscopic findings of a decrease in number and flattening of ileal type microvilli and their transformed morphologic resemblance to colonic type microvilli. All the ileal pouches also had acquired colorectal type sulphomucin, when sections stained with Alcian-blue and High Iron Diamine - Alcian blue, were studied. However, no case of pouchitis as defined in literature, was found in this study.

Endoscopic Therapy for Inflammatory Bowel Disease.

Endoscopic therapy can be employed and may be useful in inflammatory bowel disease patients with dysplastic polyps, inflammatory strictures (enteric and biliary), bleeding, and for treatment of some complications of continent ileostomies. Dysplastic polyps can be removed endoscopically safely and effectively without resorting to colectomy, as long as there is no other detectable dysplasia in flat mucosa and complete removal can be assured (by biopsy of adjacent mucosa and close follow-up). Some colonic strictures in Crohn's disease can be dilated using endoscopes of graded caliber or with through-the-scope balloons, with or without stent placement. Endoscopy is most useful in dilating anastomotic strictures and less useful for long strictures in active inflammatory disease. Strictures in ulcerative colitis are suspicious for neoplasia and, if dilated at all, should be biopsied extensively and followed closely. We prefer colectomy to endoscopic dilatation for strictures in ulcerative colitis. Biliary endoscopy can be used to dilate strictures in primary sclerosing cholangitis and to sample these areas for malignancy. Although dilatation may improve morbidity and prolong survival, it may not prevent progression to cirrhosis. In cholangiocarcinomas, endoscopic dilatation with or without stents can offer palliation and perhaps be used to deliver photodynamic therapy. Injection and sclerotherapy can be employed in Crohn's disease bleeding from a discrete site. In obstructed continent ileostomies (both Kock pouches and pelvic ileoanal reservoirs), endoscopy can be employed effectively to both determine the cause of the obstruction and re-establish patency. We do not advocate endoscopic treatment of toxic megacolon because of the heightened risk of perforation. Endoscopic therapy of Crohn's fistulas is a possible emerging technology, but it has not been used in large cohorts of patients.

Use of probiotics in the treatment of inflammatory bowel disease.

The gut flora plays a fundamental role in maintaining normal intestinal function. A disturbance of this flora, or the host response to this flora, has been clearly demonstrated to play a role in the pathogenesis of inflammatory bowel disease (IBD). This has led to attempts to modify the bacterial flora with "live non-pathogenic organisms that confer health benefits by improving the microbial balance," otherwise known as probiotics. Recent attention has focused on this potential strategy to treat or prevent IBD. The potential therapeutic benefit is enhanced by the natural and apparently safe approach that probiotics offer. Animal models of colitis have provided the proof of principle that probiotics can prevent and treat established intestinal inflammation. Controlled clinical studies have demonstrated the efficacy of probiotics in the maintenance of remission of pouchitis, prophylaxis of pouchitis after the formation of an ileoanal reservoir, maintenance of remission of ulcerative colitis, and treatment of Crohn's disease. However, large controlled trials are needed to definitively establish the place for probiotics in the treatment of IBD and resolve issues such as the dose, duration, frequency of treatment, and use of single or multiple strains. Research is focusing on establishing the mechanism of action, so that treatments with individually tailored properties are developed and innovative approaches are explored.

Effects of loperamide on ileoanal pouch function.

Opioid analogues are used to manage increased bowel frequency in patients with an ileoanal reservoir. The aim of the study was to determine the clinical efficacy of loperamide in patients with an ileoanal reservoir and to assess its effect on pouch motility. Fourteen patients with a pouch who had normal pouch emptying and anal function were studied. Ambulatory pouch and anal motility, and stool weights, were recorded for 24 h while taking no medication and for 24 h while receiving 8 mg loperamide. In a second analysis, patients were divided on the basis of bowel frequency into those with 4 or fewer motions (good function; n=6) and those with more than 6 per day (poor function; n=8), to determine any differential effects of loperamide. Loperamide decreased median bowel frequency (no loperamide 5.5 versus loperamide 4.0, P=0.03) and 24-h stool weight (610 g versus 413 g, P=0.03) but not individual stool weights. Patients with poor function had both higher bowel frequency (8.0 versus 3.5 per 24 h, P=0.004) and higher stool weight (728 g versus 430 g, P=0.05) with no treatment than those with good function. High-amplitude pouch pressure waves were greater in number before defaecation in patients with poor function and did not decrease with loperamide, in contrast to patients with good function. Pouch baseline pressure decreased after defaecation to a similar extent in both groups and was not affected by loperamide. Loperamide 8 mg per day reduces bowel frequency by reducing total stool weight, not individual stool weights. In patients with good function it also affects pouch motility. High bowel frequency is associated with increased pouch high-pressure waves.