Nonsteroidal antiinflammatory drug-induced colonic strictures: a case report

Review article: a practical approach to the clinical management of NSAID enteropathy

Co-prescription of acid suppressive therapy, together with advances in small bowel imaging techniques, have shifted the burden of NSAID-related toxicity from gastro-duodenal to more distal small bowel injury. Due to predominantly subclinical disease, NSAID enteropathy remains under-recognised, with an incidence of 53-80% amongst healthy short-term users, and a prevalence of 50-71% following long-term (>3 months) use. Despite their distinct pathogenesis, those at risk of NSAID-related gastro-duodenal and small bowel complications share several risk factors. Clinical complications of NSAID enteropathy such as protein-losing enteropathy, small bowel strictures and diaphragm disease, confer significant morbidity, and are often irreversible. Small bowel prophylaxis has proven of modest efficacy after short-term, high-dose NSAID use in asymptomatic patients. While selective COX-2 inhibitors are associated with fewer gastro-duodenal complications relative to non-selective NSAIDs, their comparative benefit in protecting against small bowel enteropathy remains unclear. Prophylaxis should be considered in those at high risk of small bowel complications, as treatment options for established disease remain limited; however, the optimal agent remains unclear. We propose a clinical algorithm that may help prevent, monitor, investigate, and manage the sequelae of NSAID-induced small bowel toxicity.

The colon: from banal to brilliant

The colon serves as the habitat for trillions of microbes, which it must maintain, regulate, and sequester. This is managed by what is termed the mucosal barrier. The mucosal barrier separates the gut flora from the host tissues; regulates the absorption of water, electrolytes, minerals, and vitamins; and facilitates host-flora interactions. Colonic homeostasis depends on a complex interaction between the microflora and the mucosal epithelium, immune system, vasculature, stroma, and nervous system. Disruptions in the colonic microenvironment such as changes in microbial composition, epithelial cell function/proliferation/differentiation, mucus production/makeup, immune function, diet, motility, or blood flow may have substantial local and systemic consequences. Understanding the complex activities of the colon in health and disease is important in drug development, as xenobiotics can impact all segments of the colon. Direct and indirect effects of pharmaceuticals on intestinal function can produce adverse findings in laboratory animals and humans and can negatively impact drug development. This review will discuss normal colon homeostasis with examples, where applicable, of xenobiotics that disrupt normal function.

Adverse effects of drugs on small intestine and colon

The small and large intestine are one of the most common sites for the adverse action of drugs, accounting for 20-40% of all drug side effects. The most important factor in the diagnosis of drug-induced intestinal side effect is awareness. The mechanisms of damage are invariably complex, but may be due to topical effects, a known pharmacologic action of the drug on motility (for instance cholinergic/anti-cholinergic effect) and/or secretion, immune suppression and in the case of cytotoxic drug treatment a combination of many actions. The diagnosis of damage may be simple and widely recognised (NSAID-induced enteropathy resulting in bleeding, protein loss and rarely perforation and diaphragm disease), or at other times ignored (tricyclic antidepressants increasing constipation) or life threatening (docetaxene). Some associations require further research (statin and anti-retroviral associated irritable bowel symptoms). Diagnosis is traditionally made by symptom improvement on discontinuation of the drug. More lately capsule enteroscopy is used to aid diagnosis.

Capsule endoscopic diagnosis of nonsteroidal antiinflammatory drug-induced enteropathy

BACKGROUND

Case reports have linked nonsteroidal antiinflammatory drugs (NSAIDs) to a variety of lesions in the small and large bowel including bleeding, protein loss, strictures, increased intestinal permeability, and NSAID enteropathy. We here review the use of wireless capsule endoscopy to quantitate and assess the nature of the small bowel damage caused by NSAIDs when taken short term and in patients on long-term NSAIDs and COX-2 inhibitors.

METHODS

Forty healthy volunteers underwent a baseline capsule endoscopy. After taking diclofenac slow-release 75 mg twice a day for a total of 14 days, both investigations were repeated. A further 120 patients on long-term NSAIDs (more than 3 months) and 40 on COX-2 inhibitors underwent a capsule endoscopy study. Sixty healthy patients acted as controls. Small bowel damage was categorized and quantitated.

RESULTS

Short-term diclofenac: Capsule endoscopy demonstrated new pathology in 27 (68%) of subjects. The most common lesions were mucosal breaks, seen in 16 (40%), which were seen to be bleeding in 2 (5%). Long-term NSAIDs: The main pathology was related to mucosal breaks (29%); 3% had free luminal blood and 2% had strictures. The damage seen in 50% of patients on selective COX-2 inhibitors did not differ significantly (P<0.5) from that seen with NSAIDs.

CONCLUSIONS

Capsule endoscopy demonstrates evidence of macroscopic injury to the small intestine, in up to 68% of volunteers, resulting from 2 weeks ingestion of slow-release diclofenac. Long-term use of NSAIDs and COX-2 inhibitors causes comparable small bowel damage (50%-68%).

Lower gastrointestinal bleeding

Lower gastrointestinal (GI) hemorrhage is a significant cause of morbidity and mortality, particularly in elderly patients. Lower endoscopic evaluation is established as the diagnostic procedure of choice in the setting of acute lower GI hemorrhage.

Non-steroidal anti-inflammatory drug (NSAID)-induced colonic strictures and perforation: a case report

Although non-steroidal anti-inflammatory drug-induced colopathy is well described, colonic perforations complicating non-steroidal anti-inflammatory drug intake are rare. We report a patient with rheumatoid arthritis who was on long-term diclofenac and presented with early colonic stricture formation and a caecal perforation, which to the best of our knowledge, has only been reported once before. It is important to suspect this diagnosis in patients on non-steroidal anti-inflammatory drug therapy who present with an acute abdomen.

Strictures, diaphragms, erosions or ulcerations of ischemic type in the colon should always prompt consideration of nonsteroidal anti-inflammatory drug-induced lesions

AIM: To investigate whether NSAIDs/ASA lesions in the colon can histologically be diagnosed on the basis of ischemic necrosis similar to biopsy-based diagnosis of NSAIDs/ASA-induced erosions and ulcers of the stomach.

METHODS: In the period between 1997 and 2002, we investigated biopsy materials obtained from 611 patients (415 women, 196 men, average age 60.5 years) with endoscopic focal erosions, ulcerations, strictures or diaphr-agms in the colon. In the biopsies obtained from these lesions, we always established the suspected diagnosis of NSAID-induced lesions whenever necroses of the ischemic type were found. Together with the histological report, we enclosed a questionnaire to investigate the use of medication. The data provided by the questionnaire were then correlated with the endoscopic findings, the location, number and nature of the lesions, and the histological findings.

RESULTS: At the time of their colonoscopy, 86.1% of the patients had indeed been taking NSAID/ASA medication for years (43.9%) or months (29.5%). The most common indication for the use of these drugs was pain (64.3%), and the most common indication for colonoscopy was bleeding (55.5%). Endoscopic inspection revealed multiple erosions and/or ulcers in 60.6%, strictures in 15.8%, and diaphragms in 3.0% of the patients. The lesions were located mainly in the right colon including the transverse colon (79.9%). A separate analysis of age and sex distribution, endoscopic and histological findings for NSAIDs alone, ASA alone, combined NSAID/ASA, and for patients denying the use of such drugs, revealed no significant differences among the groups.

CONCLUSION: This uncontrolled retrospective study based on the histological finding of an ischemic necrosis shows that the histologically suspected diagnosis of NSAID-induced lesions in the colon is often correct. The true diagnostic validity of this finding and the differentiation from ischemic colitis should, however, be investigated in a prospective controlled study.

Review article: the management of lower gastrointestinal bleeding

Several recent advances have been made in the evaluation and management of acute lower gastrointestinal bleeding. This review focuses on the management of lower gastrointestinal bleeding, especially acute severe bleeding. The aim of the study was to critically review the published literature on important management issues in lower gastrointestinal bleeding, including haemodynamic resuscitation, diagnostic evaluation, and endoscopic, radiologic, and surgical therapy, and to develop an algorithm for the management of lower gastrointestinal bleeding, based on this literature review. Publications pertaining to lower gastrointestinal bleeding were identified by searches of the MEDLINE database for the years 1966 to December 2004. Clinical trials and review articles were specifically identified, and their reference citation lists were searched for additional publications not identified in the database searches. Clinical trials and current clinical recommendations were assessed by using commonly applied criteria. Specific recommendations are made based on the evidence reviewed. Approximately, 200 original and review articles were reviewed and graded. There is a paucity of high-quality evidence to guide the management of lower gastrointestinal bleeding, and current endoscopic, radiologic, and surgical practices appear to reflect local expertise and availability of services. Endoscopic literature supports the role of urgent colonoscopy and therapy where possible. Radiology literature supports the role of angiography, especially after a positive bleeding scan has been obtained. Limited surgical data support the role of segmental resection in the management of persistent lower gastrointestinal bleeding after localization by either colonoscopy or angiography. There is limited high-quality research in the area of lower gastrointestinal bleeding. Recent advances have improved the endoscopic, radiologic and surgical management of this problem. However, treatment decisions are still often based on local expertise and preference. With increased access to urgent therapeutic endoscopy for the management of acute upper gastrointestinal bleeding, diagnostic and therapeutic colonoscopy can be expected to play an increasing role in the management of acute lower gastrointestinal bleeding.

Colon perforation with acute peritonitis after taking clindamycin and diclofenac following wisdom tooth removal

INTRODUCTION

Non-steroidal anti-inflammatory drugs have a high analgesic and anti-inflammatory effect and are widely taken for acute and chronic pain. Especially following long-term use, they may cause gastrointestinal side effects such as mucosal ulceration, perforation and strictures in the small and large bowel.

PATIENT

A 16-year-old female developed colonic perforation and purulent peritonitis after wisdom tooth removal and short-term intake of non-steroidal anti-inflammatory drugs.

DISCUSSION

Non-steroidal anti-inflammatory drugs may exert their deleterious effects on the lower gastrointestinal tract through both local and systemic actions. Systemic effects are caused by the inhibition of cyclooxygenase and reduction of protective prostaglandins. The local damage of the intestinal mucosa in the distal bowel segments seems to be caused by sustained release formulation with a high enterohepatic circulation. The latter may act time and again on the intestinal mucosa through metabolites secreted in the gallbladder. Concomitant intake of clindamycin may have favoured this acute complication.

CONCLUSION

Intestinal perforation after short-term intake of non-steroidal anti-inflammatory drugs is very rare. However, it is life-threatening and illustrates the need for careful prescribing at as low an effective dose and as short a time as possible, especially when combining different drugs. Paracetamol only has a weak effect on cyclooxygenase and continues to be a possible alternative for postoperative dental pain with a favourable benefit-risk ratio. It is the drug of choice for children, adolescents and patients with an increased risk of non-steroidal anti-inflammatory drug-induced gastro-enteropathy.

Diaphragm disease after use of nonsteroidal anti-inflammatory agents: first report of diagnosis with capsule endoscopy

Diaphragm disease of the small intestine is part of the spectrum of diseases associated with injury to the gastrointestinal tract induced by nonsteroidal anti-inflammatory drugs. Standard endoscopy or contrast studies of the small intestine rarely identify these lesions. The diagnosis usually is established at the time of surgery. We report the case of a 72-year-old woman with obscure gastrointestinal bleeding and intermittent obstruction of the small intestine who had had multiple hospitalizations and extensive testing. The patient had been treated with nonsteroidal anti-inflammatory drugs for osteoarthritis. A radiograph of the small intestine with barium contrast revealed no abnormalities, so capsule endoscopy was performed. Capsule endoscopy showed multiple small intestinal strictures beyond which the capsule could not pass. After the patient experienced continued symptoms suggestive of intermittent partial obstruction of the small intestine, computed tomography showed the capsule within a dilated loop of intestine adjacent to a stricture. After 9 days of conservative medical therapy and worsening symptoms, the patient required an exploratory laparotomy. The capsule was located in a 12-cm segment of intestine with 4 diaphragm-like lesions. Pathologic study found submucosal lesions with features identical to those of neuromuscular and vascular hamartoma (eg, mature, reactive tissue elements of smooth muscle, dense fibrous tissue, and nerve tissue bundles with scattered ganglion cells and vessels). No manifestations of Crohn disease were evident. This case represents the first diagnosis with capsule endoscopy of diaphragm disease of the small intestine with pathologic features of neuromuscular and vascular hamartoma.

Lower gastrointestinal bleeding

Lower gastrointestinal bleeding is defined as blood loss that originates from a source distal to the ligament of Treitz and results in hemodynamic instability or symptomatic anemia. Although approximately 10% to 15% of patients presenting with acute severe hematochezia have an upper gastrointestinal source of bleeding identified on upper endoscopy, the most common causes of lower gastrointestinal bleeding are diverticulosis, hemorrhoids, ischemic colitis, and angiodysplasia. As with upper gastrointestinal bleeding, lower gastrointestinal bleeding ceases spontaneously in most cases.

Non-steroidal anti-inflammatory drugs, aspirin and newly diagnosed colitis: a case-control study

BACKGROUND

There have been a number of reports of colitis following exposure to non-steroidal anti-inflammatory drugs (NSAIDs) and salicylates.

AIM

To conduct a case-control analysis of new cases of colitis, with particular reference to the usage of NSAIDs and salicylates prior to the development of the disease.

METHODS

One hundred and five consecutive new cases of colitis presenting to a single gastroenterologist were questioned about their recent usage of NSAIDs and salicylates. For comparison, the frequency of usage of these compounds was studied in two groups of 105 age- and sex-matched controls taken from hospital in-patients and community cases attending the Accident and Emergency Department.

RESULTS

Of the 105 cases of colitis studied, 78 patients (74%) had been taking NSAIDs or salicylates prior to or during the development of their disease. By comparison, 20% of community controls were using NSAIDs or salicylates (P < 0.001) and 30% of hospital in-patients were taking these compounds (P < 0.001). Comparison of these frequencies with those of the colitis group gave odds ratios of 9.1 (4.5, 21.9) with the community controls and 6.2 (3.2, 13.5) with the hospital controls.

CONCLUSIONS

In new patients presenting with colitis, there is a significantly high frequency of antecedent exposure to NSAIDs or salicylates, supporting the concept that these agents may be important in the pathogenesis of colitis.

Nonsteroidal anti-inflammatory drug-induced diaphragms and ulceration in the colon

The toxic effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the small bowel have been reported extensively. A growing number of reports of toxic effects of NSAIDs on the colon have appeared recently. The clinical presentation, endoscopic appearances and histological findings of so-called NSAID colopathy are quite varied, as illustrated by a series of four patients described in this report. Presenting symptoms and signs in this series include iron-deficiency anaemia and crampy abdominal pain, but alteration of bowel habit, weight loss, and even nausea and vomiting have also been described. One patient in this series has large-bowel diaphragms, considered by some to be pathognomonic of NSAID effects. Each of the four patients had right-sided colonic lesions only, possibly supporting a direct toxic effect of NSAIDs. Management usually involves simply stopping the offending NSAID. A review of the literature on this under-recognized entity is presented.

Epidemiology and differential diagnosis of NSAID-induced injury to the mucosa of the small intestine

Non-steroidal anti-inflammatory drugs cause small-bowel inflammation in about 60% of patients receiving these drugs long-term. The inflammation is associated with small intestinal bleeding, protein loss, ulcers and occasionally strictures. Treatment options for NSAID enteropathy include metronidazole, sulphasalazine and misoprostol, and some patients may require surgery. The diagnosis of NSAID enteropathy is not always straightforward. It is especially difficult to differentiate it from the ileitis associated with spondylarthropathy and, at times, that of Crohn's disease. An investigational algorithm is suggested for this purpose. In the last decade a number of small-bowel diseases have been identified, where none were thought to exist, because of the increasing use of enteroscopy and new sensitive tests for intestinal inflammation. Optimal treatments of these conditions are still to be studied.

Nonsteroidal anti-inflammatory drug-induced strictures of the colon: report of a case and review of the literature

The phenomenon of strictures of the colon induced by nonsteroidal anti-inflammatory drugs is a newly recognized pathologic entity that has gained little exposure in the surgical literature to date. A further case is reported and the clinical features of this entity are discussed. Most patients present with symptoms suggestive of malignancy, namely anemia, obstructive symptoms, or weight loss. Pathologic changes are characterized by diaphragm-like strictures with submucosal fibrosis. Surgical resection to exclude malignancy and treat symptoms along with cessation of the nonsteroidal anti-inflammatory drug is the treatment of choice.

Clinical and endoscopic features of nonsteroidal anti-inflammatory drug-induced colonic ulcerations

OBJECTIVE

Clinical and endoscopic features of nonsteroidal anti-inflammatory drug (NSAID)-induced colonic ulcerations have not been fully investigated.

METHODS

During a 3-yr period from April 1996 to March 1999, 6076 subjects underwent total colonoscopy at our institutions. Among them, the diagnosis of NSAID-induced colonic ulceration was made by their clinical and colonoscopic findings. All patients diagnosed as having this disease underwent upper endoscopy and follow-up colonoscopy. Clinical features, serial changes in colonoscopic findings, and upper GI lesions were analyzed.

RESULTS

Among the subjects, 14 patients were diagnosed as having NSAID-induced ulcerations. Seven patients were complicated by renal failure. Three patients had gastric ulcers concurrently. Eleven patients had colonic lesions in the ileocecal region. In 13 of 14 patients, initial colonoscopy demonstrated sharply demarcated, semilunar or circumferential ulcers without stricture formation. After discontinuance of NSAIDs, improvement of the ulcers without stricture or inflammatory polyps could be confirmed 3-10 wk later. In one patient with diaphragm-like stricture, follow-up colonoscopy performed 2 yr later demonstrated resolution of circumferential ulcer.

CONCLUSIONS

NSAID-induced colonic ulceration may occur more frequently than previously recognized. Frank ulcerations, rather than stricture formation, seem to be the typical colonoscopic signs of NSAID-induced colonic ulceration.

Eicosanoids and the small intestine

Prostaglandins play an important role in modulation of various physiologic processes in the small intestine. In this review, the involvement of prostaglandins in various small-intestinal functions including small-intestinal secretion, mucosal protection, epithelial and endothelial barrier function, and motility are discussed.

Clinical and pathologic overlap in nonsteroidal anti-inflammatory drug-related small bowel diaphragm disease and the neuromuscular and vascular hamartoma of the small bowel

Diaphragm disease (DD) is a radiographically subtle cause of small bowel obstruction and is part of the spectrum of diseases associated with nonsteroidal anti-inflammatory drug injury. The neuromuscular and vascular hamartoma (NMVH) is a nonepithelial hamartomatous, submucosally based proliferation of mature submucosal elements capable of causing small bowel obstruction. The authors report two patients in whom the clinical setting and gross pathology are that of DD, but the histologic characterization is identical to that described for NMVH. It is probable that in some patients the two diseases overlap so that some patients readily fit the criteria for both entities.

The effects of vasculitis on the gastrointestinal tract and liver

Vasculitis can affect every organ of the digestive system. In many cases, it may first present with gastrointestinal symptoms. In several forms of vasculitis, including Churg Strauss syndrome, Henoch-Schönlein purpura, and lupus, the majority of patients have gastrointestinal involvement. The astute gastroenterologist should consider vasculitic causes of the symptoms seen in many patients. Making the correct diagnosis requires a thorough understanding of the potential role of vasculitis in causing these symptoms and the appropriate path to making a diagnosis. This article reviews the variety of manifestations of vasculitis on the digestive system, and emphasizes diagnosis and clinical manifestations.

Nonsteroidal anti-inflammatory drug-associated toxicity of the liver, lower gastrointestinal tract, and esophagus

Although upper gastrointestinal (GI) adverse events are the most common consequences of nonsteroidal anti-inflammatory drug (NSAID) use, there are other GI side effects that can contribute to the morbidity and mortality associated with these drugs. NSAID-associated toxicity of the large and small bowel is increasingly recognized in clinical practice, as enteroscopic procedures become more frequently used. This lower GI toxicity may have several different manifestations: ulcerations, strictures, colitis, or exacerbation of inflammatory bowel disease. Hepatic injury, most likely due to an idiosyncratic reaction resulting from an immunologic response or altered metabolic pathways, is another sequela of NSAID use that is usually reversible. Although hepatotoxicity is listed as a class warning for NSAIDs, aspirin, diclofenac, and sulindac are most commonly associated with this problem. Surveillance for hepatic injury is not always reliable, and the low frequency of both hepatic and lower GI toxicity in NSAID users renders these events difficult to characterize. An increase in awareness, surveillance, and reporting of these events can lead to a better understanding of the risk factors and etiology associated with NSAID toxicity.

Gastrointestinal side effects of nonsteroidal anti-inflammatory drugs

The gastrointestinal (GI) tract is the most common location for side effects of nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs may cause problems in any part of the GI tract, from the esophagus to the rectum. The severity of these side effects ranges from nuisance symptoms such as dyspepsia to life-threatening ulcer complications. The diagnosis, treatment, and prevention of the various GI side effects of these commonly prescribed drugs are reviewed in this article.

Nonsteroidal-induced benign strictures of the colon: a case report and review of the literature

Colonic strictures are a rare complication reported to result from chronic use of sustained release formulations of indomethacin and diclofenac. Such strictures often present with associated mucosal ulceration and are thought to result from nonsteroidal antiinflammatory drug-induced alterations in enterocyte homeostasis. Strictures generally occur in the cecum, ascending, and proximal transverse colon with symptoms of occult blood loss, obstruction, changes in bowel habits, and rarely, perforation. The first reported case of a 69-year-old woman who developed recurrent colonic strictures with inflammatory changes and mucosal ulceration while taking Lodine (etodolac) is presented. A brief review of the relevant literature and suggested preventative therapies are discussed.

Prospective evaluation of the gastrointestinal tract in patients with iron deficiency and no systemic or gastrointestinal symptoms or signs

BACKGROUND

Although endoscopic evaluation of the gastrointestinal tract is commonly performed to evaluate iron deficiency, little data is available regarding the underlying causes, yield of evaluation, and long-term outcome for those in whom gastrointestinal and systemic symptoms and signs are absent.

METHODS

In- or out-patients seen by the gastroenterology consultative service at a large inner-city hospital over a 56-month period were considered eligible for the study when iron deficiency (serum ferritin <50 ng/mL) was documented. Exclusion criteria included: any gastrointestinal or systemic symptoms/signs, radiographic or endoscopic examinations of the gastrointestinal tract within 3 and 5 years, respectively, or obvious source of blood loss. Patients underwent colonoscopy and if no lesions other than carcinoma were found, upper endoscopy was then performed with a pediatric colonoscope.

RESULTS

Fifty-two patients were evaluated (mean age, 66 +/- 13 years; range, 20 to 89 years; 32 men/20 women). At the time of evaluation, the mean (+/-SD) hematocrit was 25% +/- 7% (range, 14% to 42%). Overall, 23 patients (44%; 95% CI 30% to 59%) had an identifiable gastrointestinal lesion considered the cause of iron deficiency, including: colonic carcinoma, 11 (21%); colonic and/or esophagogastric/duodenal vascular ectasias, 9 (17%); and gastric carcinoma, colonic polyposis, and colonic ulcers in 1 patient each. Long-term follow-up (median 24 months, range 2 to 63 months) identified only 1 patient with a cause found (colonic carcinoma), and in this patient, complete colonoscopy was not technically possible at the time of initial evaluation. There were no clinical or laboratory features that distinguished patients with an etiology for iron deficiency to the idiopathic group.

CONCLUSIONS

Approximately half of patients with iron deficiency in whom gastrointestinal or systemic signs or symptoms are absent have an underlying gastrointestinal lesion. Nevertheless, despite a thorough endoscopic evaluation, some patients will have no etiology found; the prognosis for these patients is excellent.

Clinical pharmacokinetics of diclofenac. Therapeutic insights and pitfalls

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class. When given orally the absorption of diclofenac is rapid and complete. Diclofenac binds extensively to plasma albumin. The area under the plasma concentration-time curve (AUC) of diclofenac is proportional to the dose for oral doses between 25 to 150 mg. Substantial concentrations of drug are attained in synovial fluid, which is the proposed site of action for NSAIDs. Concentration-effect relationships have been established for total bound, unbound and synovial fluid diclofenac concentrations. Diclofenac is eliminated following biotransformation to glucoroconjugated and sulphate metabolites which are excreted in urine, very little drug is eliminated unchanged. The excretion of conjugates may be related to renal function. Conjugate accumulation occurs in end-stage renal disease; however, no accumulation is apparent upon comparison of young and elderly individuals. Dosage adjustments for the elderly, children or for patients with various disease states (such as hepatic disease or rheumatoid arthritis) may not be required. Significant drug interactions have been demonstrated for aspirin (acetylsalicylic acid), lithium, digoxin, methotrexate, cyclosporin, cholestyramine and colestipol.

Acute colitis associated with etodolac

We describe two patients in whom acute colitis developed during etodolac treatment. Symptoms resolved when etodolac was stopped. In one, symptoms of colitis recurred with reexposure to the drug. The clinical and pathologic findings were consistent with de novo colitis from etodolac.

BENIGN COLONIC STRICTURES - A STUDY OF TWENTY CASES

An analysis of twenty cases of benign colonic strictures is presented. Thirteen (65%) had tubercular strictures, 3 (15%) had ulcerative colitis, one each had ischaemic colitis and Crohn's disease. In 2 cases the cause could not be established. Eleven patients (55%) presented with subacute intestinal obstruction and 7 (35%) with diarrhoea. Specific diagnoses based on histopathology could be made in only 45 per cent of cases. Most of the patients responded to specific medical therapy. Seven patients (35%) required surgical intervention.

Colonic ulceration associated with nonsteroidal anti-inflammatory drugs. Report of three cases

Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with a variety of gastrointestinal side effects. Effects on the large intestine have been reported with increasing frequency. Recognition of NSAID-induced colonic lesions has been confounded by variable clinical presentations, variable pathologic findings, and unfamiliarity of this entity among clinicians. We have recently seen three cases of NSAID-induced cecal ulcerations in patients undergoing right colectomy. A correct preoperative diagnosis was not made in our patients, one of whom presented with an acute abdomen and two in whom there was an inability to rule out carcinoma. The gross, radiographic, and histologic findings in each case consisted of a characteristic transverse ulceration with thin diaphragm-like scarring. NSAID-induced cecal ulcers can have a variety of presentations to the general surgeon, are likely to be misdiagnosed preoperatively, but may be recognized based on characteristic gross features evident by radiography and colonoscopy, along with a careful history. Review of recent literature suggests that laparotomy can be avoided when diagnosis is considered, but operation is indicated for complications, such as hemorrhage, obstruction, or perforation, and when carcinoma cannot be adequately excluded.

Influence of anti-rheumatic drugs on gut permeability and on the gut associated lymphoid tissue

There is great interest in the association between intestinal inflammation and the various arthropathies. However, most studies assessing intestinal function in these diseases are confounded by the fact that non-steroidal anti-inflammatory drugs (NSAIDs) have profound effects on the small intestine. Hence NSAIDs cause quite distinct and severe biochemical damage during drug absorption (uncoupling of mitochondrial oxidative phosphorylation proving to be most important) which results in increased intestinal permeability. All commonly used NSAIDs, apart from aspirin and nabumetone, are associated with increased intestinal permeability in man. Whilst reversible in the short term, it may take months to improve following prolonged NSAID use. Increased intestinal permeability appears to be the central mechanism of converting the biochemical damage to an inflammatory tissue reaction (NSAID enteropathy). The inflammatory enteropathy is not, however, unique to NSAIDs but similar changes are found with other permeability breakers. In intestinal infections and in diseases associated with reduced mucosal defence, suggesting that the small intestinal inflammation represents a common final pathway for a number of intestinal injuries. Spondylarthropathies are associated with a high prevalence of terminal ileitis, but as most patients have been receiving NSAIDs it has been difficult to dissociate the effects of NSAIDs on intestinal function from that of the ileitis itself. Nevertheless, two studies suggest that increased intestinal permeability in spondylarthropathies occur independently of NSAID ingestion. Whilst these findings may have implications for the development of arthritis, the permeability changes in spondylarthropathy do not differ quantitatively or qualitatively from that of NSAIDs or other permeability breakers. NSAID enteropathy can be differentiated from spondylarthropathic enteropathy by differences in location of disease and lack of predilection of certain HLA types. However, as the two may coexist both enteroscopy and ileocolonoscopy may be necessary for this distinction.

Non-steroidal anti-inflammatory drug-induced colitis

Non-steroidal anti-inflammatory drugs (NSAIDs) may adversely affect the colon, either by causing a non-specific colitis or by exacerbating a preexisting colonic disease. Patients with NSAID-induced colitis present with bloody diarrhoea, weight loss, iron deficiency anaemia and sometimes abdominal pain. Colonoscopy may be normal or may show inflammation, ulceration or diaphragm-like stricture. Histology often concludes to non-specific colitis. NSAIDs may cause perforation or bleeding of colonic diverticula, may cause relapse to inflammatory bowel disease and may exacerbate bleeding of colonic angiodysplasia. Pathogenesis of NSAID-induced colitis is still controversial. Local and/or systemic effects of NSAIDs on mucosal cells might lead to an increased intestinal permeability, which is a prerequisite for colitis. Treatment of NSAID-induced colitis should be to discontinue the drug, or at least, to reduce the dose as much as possible. Sulphasalazine and Metronidazole have been successfully used in few studies. Surgery is often indicated in case of life threatening complications or untractable symptoms.

Toxicity of nonsteroidal anti-inflammatory drugs in the large intestine

PURPOSE

Adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDS) on the upper gastrointestinal (GI) tract and small intestine are well described. Evidence is also accumulating that implicate NSAIDS in inducing and exacerbating damage in the distal GI tract. The purpose of this review is to identify possible adverse effects of NSAIDS on the large intestine and increase the clinical awareness of these toxicologic effects.

METHODS

A literature review identified the diversity of toxicologic effects induced by NSAIDS in the large intestine. The epidemiology, pathogenesis, and clinical implications of these adverse effects are described.

RESULTS

NSAID use has been associated with colonic bleeding, iron deficiency anemia, strictures, ulcerations, perforations, diarrhea, and death. In addition, NSAIDS can exacerbate inflammatory bowel disease and ulcerative colitis. The prevalence of NSAID-induced large intestinal damage is unknown. Diagnosis can be made by colonoscopy and barium scans. Although the clinical presentation of NSAID-induced gastropathy and enteropathy, bleeding or perforation, may be more dramatic than colonopathy, the overall clinical significance of these adverse effects of NSAIDS on the large intestine has not been fully characterized.

CONCLUSIONS

This review illustrates that NSAID-induced large bowel toxicity can cause significant morbidity in some patients, ranging from profuse diarrhea, chronic blood loss, and iron deficiency anemia to fatality. The pathogenesis is likely multifactorial and is thought to be related to inhibition of prostaglandin synthesis. Because NSAIDS are widely prescribed and some are available without a prescription, heightened awareness of these toxicologic manifestations throughout the GI tract may reduce morbidity.

Nonsteroidal antiinflammatory drug-induced colonic stricture. An unusual cause of large bowel obstruction and perforation

Nonsteroidal antiinflammatory drugs (NSAIDs) are widely prescribed drugs that can result in gastroduodenal ulceration. Adverse effects upon the small and large intestine are now more often recognized. Small intestinal obstruction secondary to both mucosal diaphragms and broad-based stenoses is reported, but colonic strictures appear to be less common. A case of NSAID-induced colonic stricture leading to large bowel obstruction and secondary cecal perforation (previously unreported) is presented. Twelve additional cases of NSAID-induced colonic stricture are reviewed from the literature and its possible pathogenesis is discussed.

Nonsteroidal anti-inflammatory drug-induced enteropathy: case discussion and review of the literature

The adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal tract are well described. Evidence also shows that NSAIDs can be harmful to the small intestine. The use of NSAIDs has been associated with small intestinal strictures, ulcerations, perforations, diarrhea, and villous atrophy. Herein we present a case of NSAID-induced enteropathy with multiple diaphragm-like strictures that involved the distal 35 cm of ileum and review the literature of other cases of NSAID-induced enteropathy in which biopsy specimens were obtained for histologic analysis to rule out other causes. The prevalence of NSAID-induced enteropathy is unknown. Diagnosis can be made by endoscopy or at abdominal exploration. The role of radionuclide scans for diagnosis remains unclear. The pathogenesis is likely multifactorial. Mucosal diaphragms may be specific for NSAID-related disease. Treatment options for NSAID-induced enteropathy are discussed.

Nonsteroidal anti-inflammatory drug-induced enteropathy: case discussion and review of the literature

The adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal tract are well described. Evidence also shows that NSAIDs can be harmful to the small intestine. The use of NSAIDs has been associated with small intestinal strictures, ulcerations, perforations, diarrhea, and villous atrophy. Herein we present a case of NSAID-induced enteropathy with multiple diaphragm-like strictures that involved the distal 35 cm of ileum and review the literature of other cases of NSAID-induced enteropathy in which biopsy specimens were obtained for histologic analysis to rule out other causes. The prevalence of NSAID-induced enteropathy is unknown. Diagnosis can be made by endoscopy or at abdominal exploration. The role of radionuclide scans for diagnosis remains unclear. The pathogenesis is likely multifactorial. Mucosal diaphragms may be specific for NSAID-related disease. Treatment options for NSAID-induced enteropathy are discussed.

Ulceration, fibrosis and diaphragm-like lesions in the caecum of rats treated with indomethacin

BACKGROUND

Patients on nonsteroidal anti-inflammatory drugs can develop curious intestinal fibrotic diaphragms.

METHODS

Groups of rats received indomethacin mixed into a powdered diet at 3 mg.kg/day for 6 and 12 weeks and 6 mg.kg/day for up to 6 weeks. In an attempt to reproduce a human dosing regimen, another group of rats, for a total of 30 weeks, received consecutive periods of indomethacin at 3 mg.kg/day for 12 weeks, 4.5 mg.kg/day for 1 week, 6 mg.kg/day for 1 week, control diet for 6 weeks, 4.5 mg.kg/day for 2 weeks and finally, a control diet for a healing period of 8 weeks. Control rats received powdered diet alone. At termination, the small and large intestines were examined macroscopically and histologically.

RESULTS

Indomethacin caused microcytic anaemia, hypoalbuminaemia, small intestinal ulceration, caecal ulceration and inconspicuous raised mucosal lesions in the caecum that histologically showed submucosal fibrosis with disruption and thickening of the apical muscularis mucosae. No control rats showed any abnormality.

CONCLUSION

These fibrotic lesions of the rat caecum resemble human diaphragms and may arise from healed caecal ulcers.

Duodenal diaphragmlike stricture induced by acetylsalicylic acid

Many reports have mentioned the role of nonsteroidal antiinflammatory drugs in inducing diaphragm-like strictures in the small and large bowel. These lesions are mostly seen in patients with chronic use of nonsteroidal antiinflammatory drugs. We report the case of a 57-year-old man who developed a diaphragmlike stricture in the second part of the duodenum. The patient had been using a preparation containing acetylsalicylic acid during many years. Although a congenital origin of the diaphragm is not completely excluded, we postulate that this stricture probably occurred as a result of acetylsalicylic acid-induced ulcerations, followed by submucosal fibrosis.