The immunohistological diagnosis of E. coli O157:H7 colitis: possible association with colonic ischemia

A Review of Colonoscopy in Intestinal Diseases

Since the development of the fiberoptic colonoscope in the late 1960s, colonoscopy has been a useful tool to diagnose and treat various intestinal diseases. This article reviews the clinical use of colonoscopy for various intestinal diseases based on present and future perspectives. Intestinal diseases include infectious diseases, inflammatory bowel disease (IBD), neoplasms, functional bowel disorders, and others. In cases of infectious diseases, colonoscopy is helpful in making the differential diagnosis, revealing endoscopic gross findings, and obtaining the specimens for pathology. Additionally, colonoscopy provides clues for distinguishing between infectious disease and IBD, and aids in the post-treatment monitoring of IBD. Colonoscopy is essential for the diagnosis of neoplasms that are diagnosed through only pathological confirmation. At present, malignant tumors are commonly being treated using endoscopy because of the advancement of endoscopic resection procedures. Moreover, the characteristics of tumors can be described in more detail by image-enhanced endoscopy and magnifying endoscopy. Colonoscopy can be helpful for the endoscopic decompression of colonic volvulus in large bowel obstruction, balloon dilatation as a treatment for benign stricture, and colon stenting as a treatment for malignant obstruction. In the diagnosis of functional bowel disorder, colonoscopy is used to investigate other organic causes of the symptom.

My approach to bowel ischaemia

Resections of ischaemic bowel are one of the most common pathology specimens yet are often viewed as unappealing and diagnostically unrewarding. This article serves to dispel both misconceptions. It also provides guidance on how clinical information, macroscopic handling and microscopic assessment-and especially the interlinking of all three-can maximise the diagnostic yield of these specimens. This diagnostic process requires recognition of the wide range of causes of intestinal ischaemia, including several more recently described entities. Pathologists should also be aware of when and why such causes cannot be discerned from a resected specimen and of how certain artefacts or differential diagnoses can mimic ischaemia.

Colon ischemia: A comprehensive review

The clinical and endoscopic features of colon ischemia (CI) are non-specific. CI is correctly identified at the time of presentation in only 9% of patients is. The true incidence is likely underestimated because many mild cases resolve spontaneously without medical treatment. Furthermore, since most cases of CI are transient, and no specific cause is detected they are often considered to be "idiopathic". In the setting of severe CI correct diagnosis and prompt recognition and therapy as well as identification of underlying causes are crucial for a favourable outcome. Although less severe, mild cases may present with similar symptoms, the prognosis and management are completely different and managed conservatively rather than with surgery. Unfortunately, data from most studies and current guidelines do not provide recommendations on the long-term management of CI or about the need for endoscopic follow-up to detect the development chronic, recurrent and/or ischemic colonic strictures. In this review, we focus on the definition of CI, its aetiology, and patterns of presentation. We highlight the pharmacological and/or endoscopic management as determined severity of disease that allow for improved outcomes. Prompt recognition and treatment using a multidisciplinary approach are essential for successful management of severe CI because mortality rates are significantly higher when the diagnosis is delayed.

Ischemic Colitis after Colonoscopy with Bisacodyl Bowel Preparation: A Report of Two Cases

Background

Colonoscopy is widely used for the diagnosis and management of colorectal disease and requires adequate bowel preparation. Ischemic colitis is a form of intestinal ischemia that presents with abdominal pain, diarrhea, and hematochezia. Risk factors include advanced age, cardiovascular disease, and diabetes. Both colonoscopy and bisacodyl bowel preparation have been described as rare causes of ischemic colitis with less than 35 cases collectively in the literature. Our review found that of these cases, there exists significant heterogeneity within individual patient characteristics. The majority of the cases are managed conservatively without complications or sequela. Due to the risk of ischemic colitis, the FDA has withdrawn bisacodyl bowel preparations from use in the USA. Bisacodyl bowel preparations are still used in Canada.

Cases

Here, we present two cases of ischemic colitis in previously healthy women aged 57 and 69 who underwent screening colonoscopy using bisacodyl bowel preparation. Both were treated conservatively without complications.

Conclusion

Thus far, there has been one documented case of ischemic colitis following colonoscopy with bisacodyl bowel preparation; here, we present two additional cases with one case occurring without the presence of known risk factors for ischemic colitis. Our literature review finds that there is limited evidence surrounding bisacodyl as a causative agent of ischemic colitis. Cases often contain confounding variables such as the presence of known risk factors for ischemic colitis. Our report aims to highlight the need for a more comprehensive analysis evaluating the safety of bowel preparations as well as increasing the clinical awareness surrounding the rare risk of colonoscopy-induced ischemic colitis.

Ischaemic colitis: uncertainty in diagnosis, pathophysiology and management

Ischaemic colitis is the most common form of gastrointestinal ischaemia, but may be confused with acute mesenteric ischaemia, inflammatory bowel disease or infectious colitis. This review article outlines the current classification, epidemiology and risk factors, as well as approaches about diagnosis and management to guide clinical practice. It also identifies areas for further research.

Diagnosis and management of ischemic colitis

The clinical presentation and outcome of ischemic colitis have a wide spectrum. Impaired perfusion of blood to the bowel from a variety of causes is the underlying pathophysiology. The presence of diarrhea, abdominal pain, and mild lower gastrointestinal bleeding should prompt consideration of ischemic colitis as a cause. Although many laboratory tests and radiographic images may suggest the diagnosis, endoscopic visualization of the colonic mucosa with histologic analysis of biopsies is the gold standard for identification of colonic ischemia. Many cases are transient and resolve without any complications. Medical therapy for chronic ischemia has been anecdotally proven but not carefully studied. Complications of ischemic colitis can include bowel perforation, peritonitis, persistent bleeding, protein-losing colonpathy, and symptomatic intestinal strictures. Surgical resection of the affected segment should be considered early to minimize adverse outcomes. This review describes the etiology, pathophysiology, clinical features, diagnostic approach, and management of ischemic colitis.

Retrospective analysis of disease association and outcome in histologically confirmed ischemic colitis

OBJECTIVE

To identify risk factors, clinical features and complications in patients with ischemic colitis (IC).

METHODS

All patients diagnosed with biopsy proven IC within a 2-year period were identified; clinical data were retrospectively collected and subsequently analyzed.

RESULTS

In total, 72 IC patients with a mean age of 68 years were included in this study. Among them, 18 (25.0%) were younger than 65 years with a female predominance. One-third of the patients was found to be without vascular risk factors, and 8 patients met the criteria for irritable bowel syndrome. No history of oral contraceptives or hormonal replacement therapy use could be found among the women diagnosed with IC. Over a mean duration of follow-up of 9.5 months (range 0-65 months), the rate of recurrent disease was 16.7%, while only 2 (2.8%) patients developed extra intestinal vascular sequelae. Statistical analysis identified a history of atrial fibrillation and the use of furosemide to be the only significant predictors of a poor outcome, while coronary artery disease and chronic renal failure predicted recurrence and low platelet count predicted stricture formation.

CONCLUSIONS

Although most patients with IC are elderly and have conventional vascular risk factors, it should also be considered in young patients without vascular risk factors, especially in women, who may have an atypical distribution of the disease. Severe complications and extraintestinal vascular sequelae are rare, however, residual gastrointestinal complaints and recurrent disease are relatively common and there are no reliable predictors of the outcome.

Endoscopic assessment of inflammatory bowel disease: colonoscopy/esophagogastroduodenoscopy

Endoscopy plays an important role in the initial diagnosis of IBD, including the evaluation of disease severity, activity, and extent. The implications of complete mucosal healing further confirm the function of endoscopy in the follow-up of IBD patients. The use of therapeutic endoscopy, for example stricture dilatation, can avoid the need for bowel resection. Modalities such as capsule endoscopy, EUS, NBI, CE, and other emerging techniques are likely to have an increasing role in the management of IBD, particularly in the area of dysplasia surveillance and treatment.

Colon ischemia: recent insights and advances

Ischemic colitis is the most common manifestation of ischemic injury to the gastrointestinal tract, and the variety of defined causes is increasing. Local hypoperfusion and reperfusion injury are both thought to contribute to the disease process, which manifests with a wide spectrum of injury including reversible colopathy (subepithelial hemorrhage and edema), transient colitis, chronic colitis, stricture, gangrene, and fulminant universal colitis. The distribution is typically segmental. Older studies showed that any portion of the colon can be involved; recently, it was established that the site of involvement and prognosis can be correlated. In particular, isolated involvement of the right side of the colon was shown to have a different presentation and worse outcome than ischemic colitis involving other segments. Diagnosis is usually made clinically and supported by radiologic imaging and colonoscopic evaluation. Most patients respond to conservative supportive therapy, although some with severe disease require surgical intervention.

Ischemic colitis: an analysis of 37 cases

AIM: To analyze the clinical features, endoscopic characteristics, diagnosis and treatment of ischemic colitis.

METHODS: A retrospective analysis was performed to summarize the clinical features, predisposing factors, colonoscopic findings and outcomes in 37 patients suffering from ischemic colitis.

RESULTS: Ischemic colitis occurred more often in elderly patients. In our series, 70.3% (26/37) of patients were older than 60 years. These patients often had concomitant basic diseases, such as hypertension, coronary heart disease, diabetes and cerebrovascular diseases. The main manifestations of ischemic colitis were abdominal pain and diarrhea and bloody stools. The lesions revealed by colonoscopy were mainly located in the left colon and distributed in a segmental pattern, and the pathological changes included mucosal edema, congestion, erosion and ulceration. The prognosis was good in most cases. Of all 37 patients, 27 (72.9%) almost completely recovered.

CONCLUSION: Ischemic colitis should be suspected in elderly patients with acute abdominal pain, diarrhea and bloody stools. Early colonoscopy in combination with clinical analysis is helpful for accurate diagnosis and appropriate treatment of ischemic colitis. Colonoscopy may induce ischemic colitis and should be cautiously performed.

Infectious Diseases of the Lower Gastrointestinal Tract

Gastrointestinal (GI) infections are a major cause of morbidity and mortality worldwide. Although infectious organisms are often recovered by microbiological methods, surgical pathologists play an invaluable role in diagnosis. The lower GI tract, including the appendix, large bowel, and anus, harbors a wide variety of pathogens. Some infections are part of disseminated disease, whereas others produce clinicopathologic scenarios that are specific to the lower GI tract. This review focuses on selected infectious disorders of the lower GI tract that may be encountered by the general surgical pathologist, including viral, bacterial, fungal, and parasitic organisms, and including infections caused by food- and water-borne pathogens. Diagnostic gross and histologic features are discussed, as well as useful clinical features and ancillary diagnostic techniques. Pertinent differential diagnoses are also emphasized, including other inflammatory conditions of the gut (such as ischemia or idiopathic inflammatory bowel disease) that can be mimicked by lower GI infections.

Ischemic colitis: clinical practice in diagnosis and treatment

Ischemic colitis is the most common form of ischemic injury of the gastrointestinal tract and can present either as an occlusive or a non-occlusive form. It accounts for 1 in 1000 hospitalizations but its incidence is underestimated because it often has a mild and transient nature. The etiology of ischemic colitis is multifactorial and the clinical presentation variable. The diagnosis is based on a combination of clinical suspicion, radiographic, endoscopic and histological findings. Therapy and outcome depends on the severity of the disease. Most cases of the non-gangrenous form are transient and resolve spontaneously without complications. On the other hand, high morbidity and mortality and urgent operative intervention are the hallmarks of gangrenous ischemic colitis.

Enteric infections and diagnostic testing

PURPOSE OF REVIEW

Gastrointestinal pathogens profoundly affect human health and well being. The provider's ability to render optimal care often highly depends on diagnostic microbiologic support. We aim to provide a clinically pertinent assessment of the current state of our ability to diagnose human gastrointestinal pathogens and describe (and decry) the unsophistication of many current diagnostic methods and strategies.

RECENT FINDINGS

Recent advances involve improved stool polymerase chain reaction assays and application of this technology to a broader panel of pathogens, stool antigen assays, and improved culture techniques, but there is little penetration of such diagnostic advances into clinical practice. Many such techniques remain limited to research or epidemiologic use and are not typically available in the clinical laboratory.

SUMMARY

Multiple clinical and laboratory factors need to be considered when attempting to diagnose the wide variety of gastrointestinal pathogens afflicting humans. Careful interpretation of diagnostic tests with attention to the population studied and the characteristics of each test is necessary.

Spectrum of non-inflammatory bowel disease and non-infectious colitis

A variety of inflammatory diseases of the colon, which can be differentiated from inflammatory bowel disease (IBD) and infectious colitis by their clinical, endoscopic and histological characteristics, are reported as non-IBD and non-infectious colitis. These diseases include microscopic colitis, ischemic colitis, segmental colitis associated with diverticula, radiation colitis, diversion colitis, eosinophilic colitis and Behcet's colitis. The etiopathogenesis of most of these diseases remains obscure and the epidemiological data are rather limited. These conditions are often troublesome for the patient and are associated with diagnostic difficulties for the physician. In many cases the treatment is empirical and there is a need for future research using randomized controlled trials.

Ischemic colitis: Clinical practice in diagnosis and treatment

Ischemic colitis is the most common form of ischemic injury of the gastrointestinal tract and can present either as an occlusive or a non-occlusive form. It accounts for 1 in 1000 hospitalizations but its incidence is underestimated because it often has a mild and transient nature. The etiology of ischemic colitis is multifactorial and the clinical presentation variable. The diagnosis is based on a combination of clinical suspicion, radiographic, endoscopic and histological findings. Therapy and outcome depends on the severity of the disease. Most cases of the non-gangrenous form are transient and resolve spontaneously without complications. On the other hand, high morbidity and mortality and urgent operative intervention are the hallmarks of gangrenous ischemic colitis.

[Diagnostic approach to ischemic colitis]

Ischemic colitis is the most frequent form of intestinal ischemia and arises when the colon is temporarily deprived of blood supply. Diagnosis of this entity requires a high index of clinical suspicion. To achieve this, the chronology of the symptoms (abdominal pain followed by defecatory urgency and rectorrhagia) and the clinical context in which these symptoms appear (> 90% affect persons especially at risk for vascular accidents) must be taken into account. Although diagnosis requires early colonoscopy (< 48 h), this procedure should not be performed if peritonitis is present. In severe forms, other imaging techniques, such as Doppler ultrasound or abdominal computed tomography, provide information with diagnostic -and even prognostic- value. Angiography is reserved for patients in whom there is doubt about the presence of acute mesenteric ischemia. Thrombophilia should be investigated in persons aged less than 60 years old.

Diagnosis and management of ischemic colitis

The clinical presentation and outcome of ischemic colitis has a wide spectrum. Impaired perfusion of blood to the bowel from a variety of causes is the underlying pathophysiology. The presence of diarrhea, abdominal pain, and mild lower gastrointestinal bleeding should prompt consideration of ischemic colitis as a cause. Although many laboratory tests and radiographic images may suggest the diagnosis, endoscopic visualization of colonic mucosa with histologic analysis of biopsies is the gold standard for identification of colonic ischemia. Most cases are transient and resolve without any complications. Medical therapy for chronic ischemia has been anecdotally proven but not carefully studied. Complications of ischemic colitis can include bowel perforation, peritonitis, persistent bleeding, protein-losing colopathy, and symptomatic intestinal strictures. Thus, surgical resection of the affected segment should be considered early to minimize adverse outcomes. This review describes the etiology, pathophysiology, clinical features, diagnostic approach, and management of ischemic colitis.

Verocytotoxin-producing Escherichia coli EH 0157:H7 colitis

0157:H7 is a known etiologic agent of hemorrhagic colitis. The clinical and histologic picture of colitis is largely similar to that of ischemic colitis, with areas of submucosal hemorrhage and edema, erosions, and ulcerations. We present a case report and review of the literature. A 52-year-old HIV-positive man, in apparently good immunologic condition, developed severe hemorrhagic colitis characterized by the onset of multiple colonic perforations and an unfavorable outcome. The diagnosis of 0157:H7 colitis should therefore be considered in all patients with indeterminate hematic diarrhea. Further studies are warranted to verify whether HIV infection may play a determinant role in the clinical course of 0157:H7 infection.

New developments in colonic ischemia

Colonic ischemia is the most common form of intestinal ischemia. It results from reduction in blood flow to the gastrointestinal tract, which, when prolonged, brings a spectrum of gross and microscopic changes in the affected intestinal wall. Clinical presentations range from asymptomatic to acute and fulminant, and outcomes from reversible to chronic and progressive or fulminant, with high morbidity and low mortality. This article presents an overview of colonic ischemia and discusses potential changes in imaging and treatment.

Role of acquired and hereditary thrombotic risk factors in colon ischemia of ambulatory patients

BACKGROUND & AIMS

Hypercoagulable states may play an important role in the pathogenesis of colon ischemia. Aim of this study was to assess this hypothesis investigating the role of acquired and hereditary thrombotic risk factors in patients with definite diagnosis of colon ischemia.

METHODS

We compared the frequency of antiphospholipid antibodies, protein C, protein S, and antithrombin deficiencies, factor V Leiden, prothrombin gene mutation G20210GA, and methylenetetrahydrofolate reductase C677T in 36 patients (23 men, 13 women; mean age, 64.8 years) with colon ischemia, 18 patients with diverticulitis, and 52 healthy controls.

RESULTS

The prevalence of antiphospholipid antibodies was significantly higher in patients with colon ischemia compared with inflammatory and healthy controls (19.4% vs. 0% and 1.9%). Among genetic factors, only factor V Leiden was significantly associated with colon ischemia (22.2% vs. 0% and 3.8%). A combination of thrombophilic disorders was found in 25% of the cases. Overall, one or several prothrombotic abnormalities were present in 26 patients (72%).

CONCLUSIONS

A comprehensive thrombophilic screening in colon ischemia reveals a congenital or acquired thrombophilic state in 72% of patients. Hereditary and acquired thrombotic risk factors may play an important role in the disease pathogenesis.

Infectious diarrhea in the elderly

Infectious diarrhea is an important disease in the elderly. Some basic principles have been outlined, as follows. In the elderly: Infectious diarrhea is an underappreciated health problem. There is a higher mortality rate and case-fatality rate compared with younger persons. Infectious diarrhea is most often associated with group settings (e.g., nursing homes and skilled nursing facilities) or antibiotic use. Infectious diarrhea may be associated with abnormal immune function (i.e., immunosenescence). Certain bacterial infections are commoner (e.g., C. difficile, E. coli O157:H7, and Salmonella). Some infections behave differently (e.g., Salmonella). Prompt and adequate rehydration measures are crucial. The institution of appropriate contact isolation and infection control measures is crucial in group settings.

Ischemic bowel disease in the elderly

The ischemic bowel diseases are a heterogeneous group of disorders usually seen in elderly individuals. They represent ischemic damage to different portions [figure: see text] of the bowel and produce a variety of clinical syndromes and outcomes. Colonic ischemia is the commonest of these disorders and has a favorable prognosis in most cases. In contrast, acute mesenteric ischemia, most commonly caused by a superior mesenteric artery embolus, is a disease with a poor prognosis. Acute mesenteric ischemia secondary to nonocclusive mesenteric ischemia usually is a [figure: see text] catastrophic complication of other severe medical illnesses, most notably atherosclerosis. Proper diagnosis and management of patients with ischemic bowel disease requires vigilance on the part of the physician and a willingness to embark on an aggressive plan of diagnosis and management in the appropriate setting.

Ischemic colitis during treatment with alosetron

Irritable bowel syndrome (IBS) is one of the most common entities observed by both primary care physicians and gastroenterologists. Alosetron is a potent and selective serotonin antagonist that recently became the first Food and Drug Administration-approved agent for diarrhea-predominant IBS. However, since approval, significant side effects have been noted with the use of alosetron including severe constipation, fecal impaction, and ischemic colitis. We describe a case of ischemic colitis in a male patient with IBS who was briefly treated with alosetron. Clinical, endoscopic, and pathologic features of the focal colitis strongly suggested ischemia. Symptoms correlated temporally with alosetron use, and symptoms abated with discontinuation of the drug. Endoscopic and pathologic resolution of the colitis were documented.

Clinical evaluation and management of acute severe colitis

This review concentrates on the clinical evaluation, imaging, therapy, and prognostic factors in acute severe colitis of idiopathic as well as infectious origin. Older concepts as well as more recent are critically scrutinized.

AGA technical review on intestinal ischemia. American Gastrointestinal Association

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics Committee. The paper was approved by the committee on September 25, 1999, and by the AGA Governing Board on November 25, 1999.

Colonic ischemia

Colonic ischemia encompasses a wide clinical spectrum from mild, reversible disease to severe, irreversible injury. It is a frequent disorder of the large bowel in the elderly, and can mimic certain diseases such as inflammatory bowel disease and neoplasms. The clinical course is variable, but often includes crampy, lower abdominal pain and the passage of red or maroon blood mixed with stool. In most cases, management is expectant, with supportive care and attention for signs of complicated disease. Prognosis typically is favorable, with a majority of patients completely resolving their illness; a minority go on to develop irreversible injury including strictures and chronic segmental colitis. Successful management of a patient with ischemic colitis requires a high degree of clinical suspicion, early diagnosis, careful follow-up, and prompt recognition of persistent disease.