New treatment for bile salt malabsorption

A case of COVID-19 diarrhea relieved by bile acid sequestrant administration

Patients with coronavirus disease 2019 exhibit various gastrointestinal symptoms. Although diarrhea is reported in many cases, the pathophysiology of diarrhea has not been fully clarified. Herein, we report a case of coronavirus disease 2019 with diarrhea that was successfully relieved by the administration of a bile acid sequestrant. The patient was a 59-year-old man whose pneumonia was treated by the administration of glucocorticoids and mechanical ventilation. However, beginning on the 30th hospital day, he developed severe watery diarrhea (up to 10 times a day). Colonoscopy detected ulcers in the terminal ileum and ascending colon. The oral administration of a bile acid sequestrant, colestimide, improved his diarrhea quickly. Ileal inflammation is reported to suppress expression of the gut epithelial apical sodium-dependent bile acid transporter. It decreases bile acid absorption at the distal ileum and increases colonic delivery of bile acids, resulting in bile acid diarrhea. In summary, the clinical course of the case presented in this report suggests that bile acid diarrhea is a possible mechanism of watery diarrhea observed in patients with coronavirus disease 2019.

Chronic diarrhoea in an oncology patient - Clinical assessment and decision making

Cancer survival is improving rapidly due to advances in treatments that will often involve radiotherapy, chemotherapy and novel biological agents in addition to surgery. This comes at the price of living with chronic symptoms, of which diarrhoea is particularly common. There is good evidence that for many patients these symptoms become part of everyday life, their "normality" is adjusted and symptoms are tolerated even when limiting activities severely. Clinicians often fail to appreciate the impact of these problems, as the focus of follow up tends to be on cancer recurrence. However, the rapid identification of patients in significant trouble can lead to earlier diagnosis of treatable pathologies and improvement of patients' symptoms. The aim of this review is to highlight the mechanisms which cause oncology patients to develop diarrhoea and highlight useful investigational and treatment strategies.

Chronic diarrhoea due to bile salt malabsorption: nurse-led assessment, medical treatment and dietary management

Bile salt malabsorption (BSM) occurs when bile salts, which are secreted in the small bowel to aid digestion of fats and vitamins, are not sufficiently re-absorbed in the terminal ileum. Consequently, an excess of bile salts enters the colon, causing chronic explosive diarrhoea, associated with abdominal cramps, flatulence and urgent, frequent and unpredictable bowel habits. BSM affects around 1% of the population, often occuring in ileal Crohn's disease or after ileal resection. Diagnosis begins with a nurse-led assessment, including blood and stool tests, to exclude other potential organic causes of chronic diarrhoea. BSM can then be confirmed and classified with a75Se-homocholic acid taurine (SeHCAT) scan. BSM can be treated medically with bile salt sequestrants, including colestyramine sachets, which are approved but have an unpleasant taste, and colesevelam tablets, which are more tolerable but more expensive and not yet approved. However, long-term sequestrant use can impact absorption of vitamins and other medications. BSM can also be managed with a low-fat diet, which is cost-effective and can reduce the amount of bile secreted. Nurses should provide patient education to ensure adherence and safe use.

Intestinal Absorption of Bile Acids in Health and Disease

The intestinal reclamation of bile acids is crucial for the maintenance of their enterohepatic circulation. The majority of bile acids are actively absorbed via specific transport proteins that are highly expressed in the distal ileum. The uptake of bile acids by intestinal epithelial cells modulates the activation of cytosolic and membrane receptors such as the farnesoid X receptor (FXR) and G protein-coupled bile acid receptor 1 (GPBAR1), which has a profound effect on hepatic synthesis of bile acids as well as glucose and lipid metabolism. Extensive research has focused on delineating the processes of bile acid absorption and determining the contribution of dysregulated ileal signaling in the development of intestinal and hepatic disorders. For example, a decrease in the levels of the bile acid-induced ileal hormone FGF15/19 is implicated in bile acid-induced diarrhea (BAD). Conversely, the increase in bile acid absorption with subsequent overload of bile acids could be involved in the pathophysiology of liver and metabolic disorders such as fatty liver diseases and type 2 diabetes mellitus. This review article will attempt to provide a comprehensive overview of the mechanisms involved in the intestinal handling of bile acids, the pathological implications of disrupted intestinal bile acid homeostasis, and the potential therapeutic targets for the treatment of bile acid-related disorders. Published 2020. Compr Physiol 10:21-56, 2020.

75SeHCAT scan in bile acid malabsorption in chronic diarrhoea

Chronic diarrhoea is a common entity in daily clinical practice and it leads to a loss in these patients quality of life. It may be the main symptom of multiple ethiologies including bile acid malabsorption (BAM) which has a comparable prevalence to celiac disease. The BAM results from imbalances in the homeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease or ileal dysfunction (BAM type i), it can be considered idiopathic or primary (BAM type ii) or associated with other gastrointestinal entities (BAM type iii). Among the different diagnostic methods available, ⁷⁵SeHCAT study is the primary current method due to its sensitivity, specificity, safety and low cost. The main disadvantage is that it's not available in all countries, so other diagnostic methods have appeared, such as serum measurement of FGF19 and C4, however they are significantly more complex and costly. The first-line treatment of bile acid diarrhoea is bile acid sequestrant, such as cholestyramine, which can be difficult to administer due to its poor tolerability and gastrointestinal side effects. These are less prominent with newer agents such as colesevelam. In summary, the BAM is a common entity underdiagnosed and undertreated, so it is essential to establish a diagnosis algorithm of chronic diarrhoea in which the ⁷⁵SeHCAT study would be first or second line in the differential diagnosis of these patients.

Review article: bile acid diarrhoea - pathogenesis, diagnosis and management

BACKGROUND

Bile acid diarrhoea results from imbalances in the homoeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease/dysfunction, associated with other GI pathology or can be idiopathic.

AIMS

To summarise the different types of bile acid diarrhoea and discuss the currently available diagnostic methods and treatments.

RESULTS

Bile acid diarrhoea is found in up to 40% of patients diagnosed as having functional diarrhoea/IBS-D, and in up to 80% of patients who have undergone ileal resection. It is likely under-diagnosed and under-treated. In idiopathic disease, errors in regulation feedback of fibroblast growth factor 19 contribute to the development of the condition. Clinical therapeutic trials for bile acid diarrhoea have been used to diagnose it, but the ⁷⁵ SeHCAT test is the primary current method. It is sensitive, specific and widely available, though not in the USA. Other diagnostic methods (such as serum measurement of the bile acid intermediate 7α-hydroxy-4-cholesten-3-one, or C4) have less widespread availability and documentation, and some (such as faecal measurement of bile acids) are significantly more complex and costly. First-line treatment of bile acid diarrhoea is with the bile acid sequestrant cholestyramine, which can be difficult to administer and dose due to gastrointestinal side effects. These side effects are less prominent in newer agents such as colesevelam, which may provide higher efficacy, tolerability and compliance.

CONCLUSION

Bile acid diarrhoea is common, and likely under-diagnosed. Bile acid diarrhoea should be considered relatively early in the differential diagnosis of chronic diarrhoea.

Prospective Study of Malabsorption and Malnutrition After Esophageal and Gastric Cancer Surgery

OBJECTIVE

To study malabsorption and malnutrition after curative resection of esophageal and gastric cancer.

DESIGN

Prospective cohort study.

BACKGROUND

Improved cure rates for esophageal and gastric cancer have increased focus on health-related quality of life (HR-QL) in survivorship. Although malnutrition is well described in long-term follow-up, and gastrointestinal symptoms are common, data on gut and pancreatic-related malabsorption are scant.

METHODS

Disease-free patients at least 18 months after esophageal or gastric oncologic resections represented the study cohort. A modified Gastrointestinal Symptom Rating Scale questionnaire was completed, and weight, fecal elastase (FE), albumin, vitamins, and micronutrients measured preoperatively and at 1, 6, and 18 to 24 months postoperatively. Small intestinal bacterial overgrowth (SIBO) and changes in body composition were also evaluated postoperatively.

RESULTS

At a median follow-up of 23 months, 45 of 66 patients in a consecutive series were disease-free. Mean weight (78 ± 19 vs 67 ± 16 kg), body mass index (27 ± 5 vs 24 ± 5 kg/m), Vitamin A (1.7 ± 0.6 vs 1.2 ± 0.4 umol/L), and Vitamin E (28 ± 7 vs 20 ± 7 umol/L) were significantly decreased (P < 0.01) at last follow-up compared with preoperatively. Malabsorption was evident in 73% of patients, of whom 44% had FE < 200 μg/g and 38% had evidence of SIBO. Total body fat-free mass (175 ± 96 vs 84 ± 71, P < 0.001) and skeletal muscle index (44 ± 8 vs 39 ± 8, P = 0.007) were significantly decreased at 18 to 24 months.

CONCLUSIONS

Malabsorption and malnutrition are prevalent in survivorship of esophageal and stomach cancer. This may be underappreciated, and both gut and pancreatic insufficiency represent modifiable targets in the interdisciplinary approach to recovery of HR-QL.

Quantifying bile acid malabsorption helps predict response and tailor sequestrant therapy

Although recognised as a cause of chronic diarrhoea for over forty years, diagnostic tests and treatments for bile acid malabsorption (BAM) remain controversial. Recent National Institute for Health and Care Excellence (NICE) guidelines highlighted the lack of evidence in the field, and called for further research. This retrospective study explores the BAM subtype and severity, the use and response to bile acid sequestrants (BAS) and the prevalence of abnormal colonic histology. 264 selenium-75-labelled homocholic acid conjugated taurine (SeHCAT)-tested patient records were reviewed and the severity and subtype of BAM, presence of colonic histopathology and response to BAS were recorded. 53% of patients tested had BAM, with type-2 BAM in 45% of patients with presumed irritable bowel syndrome. Colonic histological abnormalities were similar overall between patients with (29%) or without (23%) BAM (p = 0.46) and between BAM subtypes, with no significant presence of inflammatory changes. 63% of patients with BAM had a successful BAS response which showed a trend to decreased response with reduced severity. Colestyramine was unsuccessful in 44% (38/87) and 45% of these (17/38) were related to medication intolerance, despite a positive SeHCAT. 47% (7/15) of colestyramine failures had a successful colesevelam response. No patient reported colesevelam intolerance. Quantifying severity of BAM appears to be useful in predicting BAS response. Colesevelam was better tolerated than colestyramine and showed some efficacy in colestyramine failures. Colestyramine failure should not be used to exclude BAM. Colonic histology is of no relevance.

Systematic review: the management of chronic diarrhoea due to bile acid malabsorption

BACKGROUND

Bile acid malabsorption (BAM) is a common, yet under-recognised, cause of chronic diarrhoea, with limited guidance available on the appropriate management of patients with BAM.

AIM

To summarise the evidence supporting different treatments available for patients with bile acid malabsorption, noting their impact on clinical outcomes, tolerability and associated side effects.

METHODS

A literature search was conducted through PubMed, the Cochrane Database of Systematic Reviews and Scopus. Relevant articles studied patients who had been diagnosed with BAM and were clinically assessed before and after therapy.

RESULTS

A total of 30 relevant publications (1241 adult patients) were identified, which investigated the clinical response to drugs, including colestyramine, colestipol, colesevelam, aluminium hydroxide and obeticholic acid. The most commonly used diagnostic test of bile acid malabsorption was the SeHCAT test (24 studies). Colestyramine treatment was by far the most studied of these agents, and was successful in 70% of 801 patients (range: 63-100%).

CONCLUSIONS

Colestyramine and colestipol are generally effective treatments of gastrointestinal symptoms from BAM, but may be poorly tolerated and reduce the bioavailability of co-administered agents. Alternative therapies (including colesevelam and aluminium hydroxide) as well as dietary intervention may also have a role, and the promising results of the first proof-of-concept study of obeticholic acid suggest that its novel approach may have an exciting future in the treatment of this condition. Future trials should employ accurate diagnostic testing and be conducted over longer periods so that the long-term benefits and tolerability of these different approaches can be evaluated.

Colesevelam hydrochloride in the management of dyslipidemia

Dyslipidemia is a highly heterogeneous group of disorders strongly influenced by both genetic and environmental factors. Dyslipidemia significantly increases risk for atherosclerotic disease and all of its various clinical manifestations. Identifying patients with dyslipidemia and initiating therapies aimed at normalizing the lipid profile has been demonstrated to significantly reduce the risk for myocardial infarction, stroke and cardiovascular mortality in both the primary and secondary prevention settings. Guidelines in Europe, Canada and the USA emphasize the need to reduce the burden of atherogenic lipoproteins in serum and to raise levels of high-density lipoproteins in patients at risk for cardiovascular events. Statins have emerged as front-line therapy for managing dyslipidemia, especially in patients with elevated serum levels of low-density lipoprotein cholesterol. As guidelines emphasize the need to reduce serum low-density lipoprotein cholesterol to lower levels, goal attainment can be challenging. The use of combination therapy increases the likelihood of therapeutic success for many patients. Furthermore, a significant percentage of patients with dyslipidemia either cannot achieve goals on statin monotherapy, choose not to take a statin or do not tolerate these drugs due to adverse side effects, such as myalgias, weakness or hepatotoxicity. This article summarizes the pharmacology, clinical efficacy and safety of colesevelam hydrochloride, a bile acid-binding resin. Bile acid-binding resins are orally administered anion-exchange resins that are not absorbed systemically. These agents bind bile acids and reduce their reabsorption at the level of the terminal ileum and prevent their enterohepatic recirculation. Colesevelam has a favorable side effect and toxicity profile and significantly impacts serum levels of lipoproteins when used as monotherapy or when used in combination with either statins or ezetimibe.

Radiation-induced small bowel disease: latest developments and clinical guidance

Ionizing radiation is commonly used to treat a number of malignancies. Although highly effective and now more targeted, many patients suffer side effects. The number of cancer survivors has increased and so there are more patients presenting with symptoms that have arisen as a result of radiotherapy. Radiation damage to small bowel tissue can cause acute or chronic radiation enteritis producing symptoms such as pain, bloating, nausea, faecal urgency, diarrhoea and rectal bleeding which can have a significant impact on patient's quality of life. This review outlines the pathogenesis of radiation injury to the small bowel along with the prevention of radiation damage via radiotherapy techniques plus medications such as angiotensin-converting enzyme inhibitors, statins and probiotics. It also covers the treatment of both acute and chronic radiation enteritis via a variety of medical (including hyperbaric oxygen), dietetic, endoscopic and surgical therapies.

Use and indications of cholestyramine and bile acid sequestrants

Cholestyramine is a bile acid sequestrant, like colestipol and colesevelam. These molecules are positively charged non-digestible resins that bind to bile acids in the intestine to form an insoluble complex, which is excreted in the feces. They are used mainly for the treatment of primary hypercholesterolemia and hypercholesterolemia associated with mild hypertriglyceridemia, in patients not responding to dietary treatment as well as a second line-treatment for pruritus associated with cholestatic disease, in patients with incomplete biliary obstruction. Several data indicate that modulation of bile acid homeostasis has a good clinical effect in managing diabetes mellitus and the diarrhea from bile acid malabsorption. In this review, we present the "in label" use and indication for these compounds, revisiting the other clinical applications that may benefit from the use of bile acid sequestrants in the near future.

Bile acid malabsorption in inflammatory bowel disease: assessment by serum markers

BACKGROUND

Bile acid malabsorption (BAM) is a common feature of Crohn's disease (CD). We aimed to determine whether BAM develops only in patients with a resected distal ileum or if it also occurs in patients who have not undergone surgery for CD.

METHODS

The study included 347 patients with CD or ulcerative colitis (UC) and 119 healthy subjects (controls). BAM was assessed by measurement of serum levels of 7α-hydroxycholest-4-en-3-one (C4) and fibroblast growth factor 19 (FGF19). We surveyed members of the European Crohn's and Colitis Organization and International Organization for the Study of Inflammatory Bowel Disease to collect current information about BAM diagnosis.

RESULTS

The severity of BAM was associated with resection of the distal ileum. Compared with controls, patients who received moderate or extensive ileal resection had significantly increased levels of serum C4 (12 versus 62 versus 243 μg/L, respectively; P < 0.001). However, BAM was also present in a substantial number of the patients with CD who were not treated by surgery who had ileitis or colitis (14% and 11%, respectively). There was an indirect, proportional relationship between levels of C4 and FGF19 (P < 0.001).

CONCLUSIONS

The most severe BAM occurs in CD patients after resection of the distal ileum, but BAM can occur in surgically untreated CD patients, regardless of disease localization. Laboratory tests for BAM should become a part of the algorithm for diagnosis of CD to identify patients who might respond to therapies such as bile acid sequestrants. FGF19 appears to be a reliable marker of BAM.

Managing bile acid diarrhoea

Bowel symptoms including diarrhoea can be produced when excess bile acids (BA) are present in the colon. This condition, known as bile acid or bile salt malabsorption, has been under recognized, as the best diagnostic method, the (75)Se-homocholic acid taurine (SeHCAT) test, is not available in many countries and is not fully utilized in others. Reduced SeHCAT retention establishes that this is a complication of many other gastrointestinal diseases. Repeated studies show SeHCAT tests are abnormal in about 30% of patients otherwise diagnosed as diarrhoea-predominant irritable bowel syndrome or functional diarrhoea, with an estimated population prevalence of around 1%. Recent work suggests that the condition previously called idiopathic bile acid malabsorption (BAM) is not in fact due to a defect in absorption, but results from an overproduction of BA because of defective feedback inhibition of hepatic bile acid synthesis, a function of the ileal hormone fibroblast growth factor 19 (FGF19). The approach to treatment currently depends on binding excess BA, to reduce their secretory actions, using colestyramine, colestipol and, most recently, colesevelam. Colesevelam has a number of potential advantages that merit further investigation in trials directed at patients with bile acid diarrhoea.

The Role of Colesevelam Hydrochloride in Hypercholesterolemia and Type 2 Diabetes Mellitus

Objective:

To evaluate the safety and efficacy of colesevelam hydrochloride for the treatment of hypercholesterolemia and type 2 diabetes mellitus.

Data Sources:

Literature retrieval was accessed through MEDLINE/PubMed (1950–March 2010), Web of Science (1980–March 2010), and International Pharmaceutical Abstracts (1977–March 2010) using the terms colesevelam, dyslipidemia, hypercholesterolemia, and type 2 diabetes mellitus. References from publications identified were reviewed for additional resources. In addition, abstracts presented at the most recent (2009) American Diabetes Association, American Association of Clinical Endocrinologists, and European Association for the Study of Diabetes annual meetings were searched for relevant original research.

Study Selection and Data Extraction:

All articles in English identified from the data sources were evaluated. All relevant studies evaluating the safety and efficacy of colesevelam in hypercholesterolemia and/or type 2 diabetes mellitus were included. Priority was placed on data obtained from human randomized controlled trials.

Data Synthesis:

Seventeen clinical trials were reviewed and evaluated. Of the clinical trials evaluating colesevelam in hypercholesterolemia, 3 evaluated monotherapy, 4 evaluated combination therapy with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, and 6 evaluated combination therapy with other lipid-lowering therapies. In the type 2 diabetes mellitus trials, colesevelam was evaluated in combination with metformin, sulfonylureas, insulin, and rosiglitazone and sitagliptin. A review of the clinical trials provided evidence that colesevelam monotherapy effectively reduces low-density lipoprotein cholesterol (LDL-C). Additionally, the use of colesevelam in combination with other lipid-lowering therapies further reduces LDL-C. Colesevelam also effectively reduces hemoglobin A1c in patients with type 2 diabetes mellitus. The safety and tolerability of colesevelam appear to be improved from that of older-generation bile acid sequestrants, with adverse effects similar to those with placebo in monotherapy and type 2 diabetes mellitus trials.

Conclusions:

Colesevelam is a safe and effective option for the treatment of hypercholesterolemia and type 2 diabetes mellitus. It can fulfill a useful role in combination with HMG-CoA reductase inhibitors for hypercholesterolemia and should be considered in patients with type 2 diabetes mellitus with concomitant hypercholesterolemia.

Bile acids: short and long term effects in the intestine

Bile acids have secretory, motility and antimicrobial effects in the intestine. In patients with bile acid malabsorption the amount of primary bile acids in the colon is increased compared to healthy controls. Deoxycholic acid is affecting the intestinal smooth muscle activity. Chenodeoxycholic acid has the highest potency to affect intestinal secretion. Litocholic acid has little effect in the lumen of intestine compared to both deoxycholic acid and chenodeoxycholic acid. There is no firm evidence that clinically relevant concentrations of bile acids induce colon cancer. Alterations in bile acid metabolism may be involved in the pathophysiology of constipation.

Bile acid malabsoption: a forgotten diagnosis?

Bile acid malabsorption (BAM) is never life threatening but can cause chronic symptoms. A survey of senior British gastroenterologists was conducted to examine their approach to patients with potential BAM. Of the 706 gastroenterologists contacted, 62% replied. Gastroenterologists see on average 500 new patients in clinic annually; 34% have chronic diarrhoea and 1% are diagnosed with BAM. In those with chronic diarrhoea, 6% of gastroenterologists investigate for BAM first line, while 61% consider the diagnosis only in selected patients or not at all. Sixty-one per cent of patients are diagnosed with type 1 BAM (secondary to terminal ileal disease), 22% have type 2 (idiopathic bile acid malabsorption) and 15% type 3 (unrelated to terminal ileal disease). Only one third of gastroenterologists use a definitive diagnostic test for BAM. BAM (particularly type 2) is under-diagnosed because it is frequently not considered and even when considered, many patients are not subjected to definitive diagnostic testing.

Recent advances in the understanding of bile acid malabsorption

INTRODUCTION

Bile acid malabsorption (BAM) is a syndrome of chronic watery diarrhoea with excess faecal bile acids. Disruption of the enterohepatic circulation of bile acids following surgical resection is a common cause of BAM. The condition is easily diagnosed by the selenium homocholic acid taurine (SeHCAT) test and responds to bile acid sequestrants. Idiopathic BAM (IBAM, primary bile acid diarrhoea) is the condition where no definitive cause for low SeHCAT retention can be identified.

SOURCES OF DATA

Review of PubMed and major journals.

AREAS OF AGREEMENT

Evidence is accumulating that BAM is more prevalent than first thought. Management of chronic diarrhoea involves excluding secondary causes. Treatment of the condition is with bile acid binders.

AREAS OF CONTROVERSY

SeHCAT testing is not widely performed, limiting awareness of how common this condition can be. The underlying mechanism for IBAM has been unclear.

GROWING POINTS

Increasing awareness of the condition is important. Alternative mechanisms of IBAM have been suggested which involve an increased bile acid pool size and reduced negative feedback regulation of bile acid synthesis by FGF19. New sequestrants are available.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further research into the precise mechanism of IBAM is needed. Improvements in the recognition of the condition and optimization of treatment are required.

Bile acid malabsorption

Patients with bile acid malabsorption typically present with chronic, watery diarrhea. Bile acids recirculate between the liver and small intestine in the enterohepatic circulation. They are reabsorbed in the distal small intestine, and normally only a small fraction of the bile acid pool is lost to the colon during each cycle. In patients with bile acid malabsorption, a larger amount of bile acids is spilled into the colon, where the acids stimulate electrolyte and water secretion, which results in loose to watery stools. The common causes of bile acid malabsorption are ileal resection and diseases of the terminal ileum (Crohn's disease and radiation enteritis), which result in a loss of bile acid transporters and, consequently, diminished reabsorption. Bile acid malabsorption also has been documented in a small group of patients with chronic, watery diarrhea who have no demonstrable ileal disease (idiopathic bile acid malabsorption). The amount of bile acid loss to the colon determines the clinical presentation. Patients with mild to moderate bile acid malabsorption present with watery diarrhea and generally respond very well to treatment (with abolishment of diarrhea) with bile acid binders such as cholestyramine. Patients with more severe bile acid malabsorption have both diarrhea and steatorrhea. Treatment with cholestyramine is of no benefit in this group of patients and may, in fact, worsen steatorrhea. These patients are best treated with a low-fat diet supplemented with medium-chain triglycerides.

Gastrointestinal symptoms after pelvic radiotherapy: a new understanding to improve management of symptomatic patients

Gastrointestinal symptoms after pelvic radiotherapy, which affect quality of life, are substantially more common than generally recognised and are frequently poorly managed. These symptoms develop because radiation can induce change in one or more specific physiological functions in widely separated parts of the gastrointestinal tract that lie in the path of the radiotherapy beam. Radiation-induced changes are not confined by normal anatomical boundaries. Furthermore, pre-existing subclinical disease might be destabilised because of minor gastrointestinal changes induced by radiotherapy. New diseases might manifest after radiotherapy and be confused with symptoms induced by radiotherapy. Different functional deficits might cause the same symptoms. Many patients have more than one cause for their symptoms, which sometimes need very different treatments. Simple diagnostic tests that are used in other contexts, if applied appropriately to patients with new gastrointestinal symptoms after radiotherapy, can identify the underlying causes of new-onset symptoms. Starting treatment without knowing the cause of the symptom is commonly ineffective because prediction of the combination of treatments needed is difficult. Evidence suggests that many patients have unusual but highly treatable malfunctions of gastrointestinal physiology, which if correctly diagnosed may enable a patient with difficult symptoms to be helped.

Gastrointestinal problems after pelvic radiotherapy: the past, the present and the future

Up to 300,000 patients per year undergo pelvic radiotherapy worldwide. Nine out of 10 will develop a permanent change in their bowel habit as a result. Five out of 10 of all patients will say that this change in their bowel habit affects quality of life and two to three out of 10 will say that this effect on quality of life is moderate or severe. Between one in 10 and one in 20 patients will develop very serious complications within the first 10 years after treatment. This number will increase to two out of 10 by 20 years from the end of treatment. Although research carried out into the basic molecular, cytokine and physiological changes underlying radiation-induced bowel symptoms and the optimal treatment that should be provided to symptomatic patients is scant, it does seem probable that a significant proportion of these patients can be cured or improved by specialist gastroenterological intervention. However, most patients never get referred to a specialist gastroenterologist and research into late radiation bowel damage has not been considered a priority. With the advent of more effective cancer therapies leading to greater numbers of affected long-term survivors, much more emphasis is urgently required to provide better information to patients at the start and after treatment, developing techniques that might reduce the frequency of significant bowel toxicity and researching better ways of measuring and treating late-onset side-effects.

Faecal incontinence: A late side-effect of pelvic radiotherapy

AIMS

Despite advances in pelvic radiotherapy, damage to normal tissue can lead to chronic gastrointestinal problems. The frequency with which this affects quality of life is controversial. Faecal incontinence is not widely perceived to be a major issue after pelvic radiotherapy. The aim of this paper is to review the frequency and mechanisms for the development of faecal incontinence after pelvic radiotherapy, and to review treatment options for faecally incontinent patients.

MATERIALS AND METHODS

A search of original literature was carried out using MEDLINE and EMBASE databases from 1966 to 2005.

RESULTS

The reliability of the published data is poor because patients frequently fail to admit to faecal incontinence, and because prospective studies are lacking that assess faecal incontinence as a specific end point using adequate, validated and reproducible methodology. The published rates of late new-onset faecal incontinence after pelvic radiation are between 3% and 53%. Patients treated for prostate rather than gynaecological, bladder, rectal or anal cancer may have a lower rate. Only 8-56% of affected patients state that faecal incontinence reduces their quality of life. Studies examining the physiological changes occurring after radiotherapy are generally not adequately controlled or powered, assessment of ano-rectal function is rarely comprehensive and loss of patients to follow-up frequently makes it difficult to extrapolate results to a wider population. Where there is agreement over the physiological changes that occur after radiotherapy, it is not clear at what threshold these changes cause symptoms. No prospective studies of any non-surgical treatment for faecal incontinence after radiotherapy have been published. Surgery other than colostomy probably carries a high risk of complications in this group of patients, but few data have been published.

CONCLUSIONS

Now that improvements in outcome from combination treatments, including radiotherapy for pelvic cancer, are being achieved, it is time that serious attention is paid to determining how frequently significant gastrointestinal toxicity arises, and how best to optimise the quality of life of long-term survivors.