Indium-111-labeled autologous leukocyte imaging and fecal excretion

This study was designed to evaluate the role of¹¹¹In-labeled leukocyte imaging and fecal excretion in the assessment of inflammatory bowel disease. We compared these tests to various indices of disease activity in Crohn's disease, to Truelove's grading in ulcerative colitis, and to endoscopy, x-ray, and pathology in both diseases. Eleven controls, 16 patients with Crohn's disease, 13 with ulcerative colitis, and 3 with other types of acute bowel inflammation were studied (positive controls). Indium scanning was performed at 1,4, and 24 hr. Fourteen of 16 patients with active Crohn's disease had positive scans but in only five was localization accurate. One patient had inactive ulcerative colitis, and the scan was negative. Of 12 patients with active ulcerative colitis, 10 had positive scans but disease localization was accurate in only four. Disease extent was correctly defined in 1 of the 3 Positive Controls. There was no significant difference in the accuracy of scanning at 1,4 or 24 hr.¹¹¹In fecal excretion was significantly higher in patients with inflammatory bowel disease than in controls, and there was correlation between¹¹¹In fecal excretion and most of the indices of disease activity in Crohn's disease. In ulcerative colitis,¹¹¹In fecal excretion did not correlate with Truelove's grading but reflected colonoscopic assessment of severity. In conclusion,¹¹¹In-labeled leukocyte scanning lacks sensitivity with respect to disease extent, but fecal excretion of¹¹¹In correlates well with disease severity as determined by other methods.Supported by the Physicians' Services Incorporated and the Medical Research Council of Canada grant MT. 4257     

Differing acute phase responses in Crohn's disease and ulcerative colitis.

Thirty eight patients with Crohn's disease and 30 patients with ulcerative colitis have been assessed using the technique of faecal excretion of 111Indium granulocytes to quantify precisely acute inflammatory activity. At the time of each faecal granulocyte measurement the serum concentration of the acute phase protein C-reactive protein and the erythrocyte sedimentation rate were estimated. C-reactive protein concentration was significantly higher in Crohn's disease than ulcerative colitis both overall and particularly in relation to given levels of granulocyte excretion. No such distinction was observed between the erythrocyte sedimentation rates in the two diseases. The present findings show that the acute phase response differs significantly between Crohn's disease and ulcerative colitis. Patients with ulcerative colitis may be constitutionally different from those with Crohn's disease and unable to mount a major acute phase response to their own disease.     

111Indium autologous granulocytes in the detection of inflammatory bowel disease.

Indium leucocyte scanning and measurement of faecal Indium leucocyte excretion are techniques which have recently been introduced for assessing patients with inflammatory bowel disease. The methodology has recently been made more specific for acute inflammation by labelling pure granulocytes rather than the mixed leucocyte preparation. To determine the accuracy of this modified technique in detecting inflammatory bowel disease, we have prospectively compared Indium granulocyte scanning and faecal In granulocyte excretion with rectal histology and contrast bowel radiology as screening procedures in 100 patients with suspected inflammatory bowel disease. Thirty three patients were shown to have inflammatory bowel disease - 24 with Crohn's disease and nine with ulcerative colitis or indeterminate colitis. Overall the respective sensitivities for detecting inflammatory bowel disease were 97% for faecal Indium granulocyte excretion, 94% for Indium granulocyte scanning, 79% for radiology and 70% for rectal histology. The superiority of In granulocytes over radiology and rectal histology in detecting inflammatory bowel disease was, in the main, due to the difficulty in diagnosing Crohn's with conventional techniques. Although three of the patients with ulcerative colitis and indeterminate colitis had normal sigmoidoscopic appearances - all had abnormal rectal histology. No patient with a non-inflammatory bowel disorder had a positive In granulocyte scan or a raised faecal excretion. These results show that investigations using In granulocytes are accurate in identifying inflammatory bowel disease and offer important advantages over conventional procedures for detecting Crohn's disease.     

Inflammatory bowel disease and leukemia

In a review of a large number of patients with inflammatory bowel disease, leukemia was observed in five patients with chronic ulcerative colitis and in two patients with Crohn's disease. In ulcerative colitis patients, there were three cases of acute myelocytic leukemia and one case each of acute lymphoblastic leukemia and chronic granulocytic leukemia. In Crohn's disease patients, there was one case each of chronic granulocytic leukemia and chronic lymphocytic leukemia associated with thrombocythemia. Sixteen other cases of leukemia have been reported to date in inflammatory bowel disease. All types of leukemia, but particularly acute myelocytic leukemia, have been described. There has been no single common feature as to type (whether ulcerative colitis or Crohn's disease), extent and course, or medical and surgical treatment of the bowel disease. The relative risk of leukemia in patients with ulcerative colitis was 5.3 [95% confidence interval 1.7 to 12.3 (P<0.01)] and of acute myelocytic leukemia 11.4 [95% confidence interval 2.3 to 24.9 (P<0.01)]. Our data on patients with Crohn's disease were not sufficient to assess the statistical significance of leukemia in this disease. This study suggests that there may be an increased risk of leukemia, particularly acute myelocytic leukemia, in ulcerative colitis. The causal relationship, if any, remains undetermined.     

Update on the etiology, pathogenesis and diagnosis of ulcerative colitis

Evidence is accumulating that both genetic and environmental factors contribute to ulcerative colitis. The most consistent genetic associations have been shown for the MHC locus HLA Class II alleles, but the interleukin-1 family of genes and the multidrug resistance gene MDR1 have also been implicated as genetic susceptibility factors for the development of disease. In addition, there is a relationship between ulcerative colitis and bacterial flora, with an increased number of adherent Bacteroides spp. and Enterobacteriaceae spp. present in inflamed bowel segments. Conversely, cigarette smoking and appendectomy have both been shown to protect against the development of ulcerative colitis. Despite our improved understanding of the genetics and inflammatory mechanisms that underpin this disease, however, the etiology and pathogenesis of ulcerative colitis remain undefined. The diagnosis of ulcerative colitis is being aided by recent advances in diagnostic strategies, including the detection of fecal and serologic markers and the use of wireless capsule endoscopy, but, in the absence of a pathognomonic marker, the definition of this disease remains based on well-established clinical, endoscopic and histologic criteria. In particular, it is difficult to discriminate ulcerative colitis from other forms of colitis, including Crohn's disease, and there seems to be a growing overlap of pathophysiologic processes between ulcerative colitis and post-infectious irritable bowel syndrome. Patients who remain indeterminate between ulcerative colitis and Crohn's disease also continue to be a diagnostic challenge.     

Sabin-Feldman dye test in ulcerative colitis and Crohn's disease

The prevalence of Toxoplasma infection among patients with inflammatory bowel disease was studied. The Sabin-Feldman dye test was performed on 35 patients with Crohn's disease, 44 patients with ulcerative colitis, and 140 control patients. A higher incidence of positive reactions was found in Crohn's disease patients over the age of 40 (P<0.05). All other factors showed no significant differences among the three groups of patients. These factors include age younger than 40 years, sex, duration of disease, extent of disease, and type of treatment. It is concluded that there is no correlation between inflammatory bowel diseases and toxoplasmosis. Toxoplasma infection, however, should be considered in patients with Crohn's disease who are over 40 years old, and who present with nonspecific signs of intercurrent infection.     

Identification of a prodromal period in Crohn's disease but not ulcerative colitis

OBJECTIVES: Irritable bowel syndrome, a common gastrointestinal diagnosis, has not been clearly studied in inflammatory bowel disease. Some of the residual symptoms in subjects treated with Crohn's disease and ulcerative colitis are thought to be related to irritable bowel syndrome. The aims of this study were 1) to describe the duration and nature of complaints before the diagnosis of Crohn's disease and ulcerative colitis (prodromal period), and 2) to determine the role of IBS in this prodromal period. METHODS: A total of 66 patients with confirmed inflammatory bowel disease were enrolled in the study. The subjects received a questionnaire to ascertain the nature and duration of symptoms preceding the diagnosis of Crohn's disease or ulcerative colitis, including features described under the Rome criteria for irritable bowel syndrome. RESULTS: Of the 66 subjects analyzed, 45 had Crohn's disease and 21 had ulcerative colitis. The prodromal period was 7.7 +/- 10.7 yr for Crohn's disease and 1.2 +/- 1.8 yr for ulcerative colitis (p < 0.05). Once patients meeting the Rome criteria for irritable bowel syndrome during the prodrome were excluded, the duration of the prodromal period (non-IBS) for ulcerative colitis dropped to 0.8 +/- 1.3 yr compared to 6.9 +/- 9.8 yr in the Crohn's disease group (p < 0.05). The symptoms of the non-IBS prodrome in subjects with Crohn's disease were bloating, diarrhea, stomach pain, heartburn, fever, weight loss, and fatigue. Further analysis demonstrated that subjects whose Crohn's disease initially began as colonic disease had a longer prodrome than with small bowel. In the non-IBS Crohn's group, there was also a correlation between the age at the time of diagnosis and the duration of prodrome (r = 0.67, p < 0.0001). CONCLUSIONS: There is a significant prodromal period before the time of diagnosis of Crohn's disease that is not found in ulcerative colitis even after exclusion of subjects with IBS.     

Fulminant colitis in inflammatory bowel disease

PURPOSE: The morphologic features of fulminant colitis may be nonspecific, making differentiation between ulcerative colitis and Crohn's disease difficult, even after colectomy. The aims of this study were 1) to identify histologic features that accurately differentiated ulcerative colitis, Crohn's disease, and indeterminate colitis in fulminant colectomy specimens; 2) to determine how frequently subsequent clinical course altered the pathologic diagnosis; and 3) to evaluate the natural history of histologically diagnosed indeterminate colitis. METHODS: Ninety-five fulminant colectomy specimens were evaluated, of which 85 had an original diagnosis of fulminant inflammatory bowel disease. Complete pathologic material and comprehensive clinical follow-up information was available on 67 cases of inflammatory bowel disease. These were re-evaluated in a blinded fashion, and histopathologic features were compared with the original diagnosis and reviewed in the light of subsequent clinical behavior to reach a final diagnosis. RESULTS: Evaluation of macroscopic features was not helpful in differentiating ulcerative colitis from Crohn's disease. Microscopic examination correctly diagnosed ulcerative colitis or Crohn's disease in only 58 of 67 (87 percent) cases. A further three cases (4 percent) were definitively classified after correlation with clinical data, leaving a residual six cases that were diagnosed as indeterminate colitis. Granulomas and lymphoid aggregates were the two most specific indicators of Crohn's disease. CONCLUSIONS: Histopathologic evaluation alone has limitations in the accurate classification of fulminant inflammatory bowel disease. Histologically diagnosed indeterminate colitis is a heterogeneous group that may include some patients who subsequently prove to have ulcerative colitis or Crohn's disease.Presented at the meeting of the United States and Canadian Academy of Pathology, Orlando, Florida, March 1 to 7, 1997.     

Bone mineral density is reduced in patients with Crohn''s disease but not in patients with ulcerative colitis: a population based study.

BACKGROUND: Patients with inflammatory bowel disease are at risk of developing metabolic bone disease. AIMS: To compare bone mineral density in patients with Crohn's disease with patients with ulcerative colitis and healthy subjects, and to evaluate possible risk factors for bone loss in inflammatory bowel disease. PATIENTS: 60 patients with Crohn's disease, 60 with ulcerative colitis, and 60 healthy subjects were investigated. Each group consisted of 24 men and 36 women. METHODS: Lumbar spine, femoral neck, and total body bone mineral density were measured by dual x ray absorptiometry (DXA), and Z scores were obtained by comparison with age and sex matched normal values. RESULTS: Mean Z scores were significantly lower in patients with Crohn's disease compared with patients with ulcerative colitis and healthy subjects. Patients with ulcerative colitis had bone mineral densities similar to healthy subjects. Use of corticosteroids, body mass index (BMI), and sex were significant predictor variables for bone mineral density in Crohn's disease. In ulcerative colitis only body mass index and sex were of significant importance. Disease localisation and small bowel resections had no influence on bone mineral density in patients with Crohn's disease. CONCLUSIONS: Patients with Crohn's disease have reduced bone mineral density. Several factors are probably involved, but the reduction is associated with corticosteroid therapy. When studying skeletal effects of inflammatory bowel disease, patients with Crohn's disease and those with ulcerative colitis should be evaluated separately.     

Anergy to dinitrochlorobenzene and depression of T-lymphocytes in Crohn's disease and ulcerative colitis.

Skin reactivity to dinitrochlorobenzene (DNCB) and levels of circulating T-lymphocytes were measured in 15 patients with ulcerative colitis, 15 patients with Crohn's disease, and 12 normal control subjects. Diminished reactivity to DNCB was demonstrated in 87% of patients with Crohn's disease (P less than 0-001) and in 53% with ulcerative colitis (P less than 0-02), as compared with only 8-5% of controls; anergy was more frequent in Crohn's disease than in ulcerative colitis (P less than 0-05). Levels of circulating T-lymphoctes were also depressed in both Crohn's disease and ulcerative colitis (P less than 0-001) as compared with controls, with the values lower in Crohn's disease than in ulcerative colitis (P less than 0-02). There were no correlations of DNCB response with extent, duration, or severity of disease nor with T-cell levels within any patient group. These data provide further support for the concept that there is impairment of cell-mediated immunity among many patients with chronic inflammatory bowel disease, including both Crohn's disease and ulcerative colitis.     

Mucosal metabolism in ulcerative colitis and crohn's disease

PURPOSE: Colonic mucosal metabolism of butyrate may be impaired in ulcerative colitis. In this study we sought to confirm this observation, to determine if a similar change occurs in Crohn's colitis, and to establish whether a panenteric disorder of butyrate metabolism exists in either condition. METHODS: With use of a microculture technique, mucosal metabolic fluxes of¹⁴[C]-labeled butyrate and¹⁴[C]-labeled glutamine were measured as¹⁴[C] carbon dioxide production in mucosal biopsy specimens from the colon and ileum in patients with ulcerative colitis, Crohn's colitis, and healthy bowel. Results were expressed as pmol/µg biopsy DNA/hour. RESULTS: In the colon the mucosal metabolic fluxes of both butyrate and glutamine are reduced in both ulcerative colitis and Crohn's colitis compared with healthy controls. These changes were most marked in the presence of moderate to severe mucosal inflammation, there being no significant difference in mucosal metabolic flux between mildly inflamed mucosa and healthy controls. In the ileum the mucosal metabolic fluxes of butyrate and glutamine did not differ between healthy controls and those with either ulcerative colitis or Crohn's colitis. CONCLUSIONS: Changes in colonic mucosal metabolism of butyrate and glutamine in inflammatory bowel disease occur as a consequence of the inflammatory process and are not peculiar to ulcerative colitis. Ileal mucosal metabolism is unchanged in ulcerative colitis and Crohn's colitis, indicating the absence of a panenteric abnormality of mucosal metabolism in these two conditions.Supported by the Mater College, Dublin, Ireland.Portions of this work were read at the American Gastroenterological Association San Francisco, California, May 19 to 24, 1996, and an abstract was published in Gastroenterology 1996;110:A900.     

Immunoglobulin G (IgG), IgG1, and IgG2 determinations from endoscopic biopsy specimens in control, Crohn's disease, and ulcerative colitis subjects.

Acute exacerbations of chronic inflammatory bowel disease (ulcerative colitis and Crohn's disease) are characterised by an increase in immunoglobulin G (IgG) positive cells in the mucosa, whereas uninflamed mucosa of inflammatory bowel disease patients displays only moderately increased or normal numbers of these cells. Previous data suggest that acute exacerbations of ulcerative colitis and Crohn's disease can be distinguished by different IgG subclass expression of mucosal immunocytes and a different IgG subclass production pattern of lamina propria lymphocytes. A procedure to obtain enough intestinal mononuclear cells from biopsy specimens to measure in vitro IgG and IgG1 production in control subjects and various patient groups has been established. IgG2 could be measured in Crohn's disease and ulcerative colitis only, as the concentrations in control subjects were below the sensitivity of the ELISA method. We found that IgG and IgG1 production correlated with the degree of local inflammation in both diseases, even in slightly inflamed mucosa, compared with control subjects. The proportion of IgG1 subclass was significantly increased in severely inflamed mucosa of both ulcerative colitis and Crohn's disease patients. A major difference between Crohn's disease and ulcerative colitis mucosa is apparent in mild or no inflammation. In Crohn's disease mucosa in remission, the IgG1/IgG ratio is comparable with that in controls, yet ulcerative colitis mucosa still displays significantly increased proportions of IgG1. In addition, the IgG2/IgG ratio is 0.12 in ulcerative colitis and 0.19 in Crohn's disease patients. The results show the dependence of local IgG and IgG1 production on the degree of inflammation and that an increase in subclass IgG1 in ulcerative colitis is present at all stages, including remission. These findings support the hypothesis that different immunoregulatory mechanisms are involved in Crohn's disease and ulcerative colitis. Environmental stimuli or genetic background may be responsible for the observed differences.     

Utility of a Rapid Fecal Latex Agglutination Test Detecting the Neutrophil Protein, Lactoferrin, for Diagnosing Inflammatory Causes of Chronic Diarrhea

Objective: The utility of tests for fecal neutrophils in the setting of chronic diarrhea has not been established. The purpose of this study was to determine the causes of chronic diarrhea associated with fecal neutrophils.
Methods: One fecal specimen from each of 10 normal subjects, 26 patients with known microscopic colitis, 13 with celiac sprue, eight with Crohn's disease, four with ulcerative colitis, and 103 with chronic diarrhea of unknown origin, as well as 10 fecal specimens from a patient with chronic nongranulomatous enterocolitis were analyzed blindly for the presence of a neutrophil granule protein called lactoferrin using a commercial latex agglutination kit. Diagnostic evaluation of the 103 patients with chronic diarrhea was carried out to determine the diagnostic accuracy of this test for chronic inflammatory bowel disease.
Results: None of the normal control subjects, three of 39 patients with microscopic colitis or celiac sprue, all 10 specimens from the patient with enterocolitis, and all 12 control patients with ulcerative colitis or Crohn's disease had a positive fecal lactoferrin test. Eleven of 103 patients with chronic diarrhea presenting without a diagnosis had a positive test, and all were diagnosed with an inflammatory condition of the colon (five-, ulcerative colitis; four-, Crohn's disease; one-, ischemic colitis; and one-, microscopic colitis). Only one patient with inflammatory bowel disease had a negative lactoferrin test. The sensitivity, specificity, and positive and negative predictive values of the fecal lactoferrin test for ulcerative or Crohn's colitis were 90%, 98%, 82%, and 99%, respectively.
Conclusion: The major cause of fecal neutrophils in patients with chronic diarrhea is chronic inflammatory bowel disease of the colon. The latex agglutination test for fecal lactoferrin offers a highly sensitive, specific, and simple means for detection of fecal neutrophils in these patients.     

Indeterminate colitis

The term indeterminate colitis has been used to describe cases of inflammatory bowel disease that cannot be classified as ulcerative colitis or Crohn's disease. However, this term has suffered varying definitions, which in addition to numerous difficulties in diagnosing inflammatory bowel disease has led to much confusion. The term indeterminate colitis should only be used in cases where a colectomy has been performed and the overlapping features of Crohn's disease and ulcerative colitis do not allow a definitive diagnosis. Over time the majority of patients remain with a diagnosis of indeterminate colitis, or show symptoms similar to ulcerative colitis. Ileal pouch-anal anastomosis surgery can be performed in such patients, with outcomes of pouch failure and functional outcome that are similar to those in patients with ulcerative colitis but with increased risk of postoperative pouch complications. This review addresses the definition of indeterminate colitis, its pathology, natural history, and outcomes of restorative proctocolectomy.     

Biological therapies for ulcerative colitis

Biological therapies are being increasingly investigated for the treatment of inflammatory bowel disease. However, a great deal more study has been devoted to studies of Crohn's disease rather than ulcerative colitis. Ulcerative colitis, like Crohn's disease, represents an area of high clinical need, particularly for those patients who have disease inadequately responsive to corticosteroids and 5-aminosalicylates. The distinct anatomic distribution of inflammation in ulcerative colitis represents an important model for study, with the entire involved mucosa entirely accessible to endoscopy. In addition, there is an opportunity for local delivery of biologic agents in left-sided disease. Distinct pathogenetic factors in ulcerative colitis raise the possibility of therapies quite different from those used in Crohn's disease. This work describes the current state of knowledge regarding biological therapy in ulcerative colitis. The role of probiotic therapy, and studies of cytokine-directed therapies, therapies targeting adhesion and recruitment, and restitution and repair are described.     

Bile acid malabsorption in children and adolescents with chronic colitis

Bile acid malabsorption was measured as the fecal excretion of 14C after intravenous administration of carboxyl-14C-cholic acid and was studied in 31 patients, 8-17 years old, with chronic colitis. There were 15 patients with proven or probable Crohn's disease and 16 patients with ulcerative colitis. The mean excretion was 14.7% and 19.9%, respectively. The patients with moderate or severe inflammatory activity in the ascending colon, assessed by colonoscopy, had a significantly higher 14C excretion than the patients with no or mild inflammatory activity, 24.1% and 6.6%, respectively. These findings suggest that the ascending colon is more important in the preservation of bile acids than has usually been postulated. When the inflammation in this part of the colon is pronounced, the 14C excretion is high, independent of the type of colitis and the clinical disease activity.     

Evolving concepts on inflammatory bowel disease. Are we happy with the present nosology?

The term inflammatory bowel disease traditionally comprises ulcerative colitis, Crohn's disease and indeterminate colitis, an intermediate variant of the two major forms. The term is commonly used in the literature and in clinical practice even though it has never been revised in a Consensus Conference. The present nosology of inflammatory bowel disease seems not to be entirely satisfactory as it is limited to chronic diseases only and does not include several recently described idiopathic inflammatory bowel disorders. Although the aetiology of inflammatory bowel disease remains unknown, both ulcerative colitis and Crohn's disease are characterized by a similar pathogenesis which consists in a persistent intestinal inflammation resulting from disregulation of the gut mucosal immune system. The pathogenetic mechanisms could, therefore, provide a suitable criterion for the classification of idiopathic inflammatory bowel disease. A revised classification of inflammatory bowel disease is thus proposed. It seems reasonable to subclassify inflammatory bowel disease into acute and chronic forms. Acute forms should include the sudden attacks of ulcerative colitis and Crohn's disease with rapid and complete resolution and the so-called "acute self-limited colitis". The chronic forms should comprise, besides the classical forms of ulcerative colitis, Crohn's disease and indeterminate colitis, also other idiopathic inflammatory bowel conditions such as collagenous colitis, lymphocytic colitis and eosinophilic gastroenteritis.     

Faecal mucus degrading glycosidases in ulcerative colitis and Crohn's disease.

Because the normal faecal flora includes bacteria which can produce mucus-digesting glycosidases, it follows that increased digestion of colonic mucus by these bacterial enzymes could be important in the pathogenesis of ulcerative colitis. Faecal activities of potential mucus-degrading glycosidases have therefore been assayed in samples from patients with inflammatory bowel disease and normal controls. The enzymes alpha-D-galactosidase, beta-D-galactosidase, beta-NAc-D-glucosaminidase alpha-L-fucosidase and neuraminidase were assayed. Considerable glycosidase activity was present in most faecal samples. Similar activities of all the enzymes assayed were found in faeces from patients with ulcerative colitis, Crohn's disease and normal controls and there was no significant correlation with disease activity. These results imply that relapse of ulcerative colitis is not initiated by increased degradation of colonic mucus by faecal glycosidases but do not exclude a role for bacterial mucus degradation in the pathogenesis of ulcerative colitis.     

Mortality from Crohn's disease and ulcerative colitis in England-Wales and the U.S. from 1950 to 1983

As the etiology of inflammatory bowel disease remains unknown, studies of its time trends may provide clues to understanding the underlying mechanisms. This study examines mortality from Crohn's disease and ulcerative colitis in England and Wales and the U.S. during the period 1950 to 1983. Mortality from Crohn's disease and ulcerative colitis changed in both countries similarly. The death rates from Crohn's disease increased until 1970 to 1974 and decreased thereafter. The death rates from ulcerative colitis decreased throughout the observation period. Similar time trends occurred in men and women, and in the U.S. in whites and nonwhites. In the U.S., the death rates from both diseases were twofold higher in whites than nonwhites. The temporal changes suggest that mortality from inflammatory bowel disease is affected by exogenous factors and that these factors are different for Crohn's disease than for ulcerative colitis. These factors seem to have changed similarly in England and in the U.S. Supported by grant So 172/1-1 from the Deutsche Forschungsgemeinschaft.     

Intestinal Permeability to 99mTc-Diethylenetriaminopentaacetic Acid in Inflammatory Bowel Disease

Intestinal permeability in inflammatory bowel disease and its relation to periods of disease activity has been investigated by measuring the urinary excretion of DTPA labeled with 99mTc. Urine excretion in 10 control subjects was 2.7 +/- 1% of the test dose. Twelve patients with ulcerative colitis excreted 5.08 +/- 1.6% in remission, 10.61 +/- 2% during periods of mild activity, 19.41 +/- 0.9% during moderate activity, and 15.41 +/- 6.3% with severe activity. Sixteen patients with Crohn's disease excreted 5.7 +/- 1.9% in remission, 8.47 +/- 2.8% during mild activity of the disease, and 14.29 +/- 5.8% during moderate activity. No differences were observed between ulcerative colitis and Crohn's disease, or between ileal and colonic forms of Crohn's disease. Excretion in remission was significantly greater than in control subjects and there was a correlation between excretion and disease activity. In serial determinations done in seven patients we found that urine excretion of the test substance correlated with disease activity. We also studied DTPA excretion in 10 cases with gastric or duodenal ulcer (2.28 +/- 1.4%), six cases of acute gastroenteritis (4.87 +/- 3.1%) and nine cases with other intestinal diseases (3.6 +/- 1.1%). In all these cases, DTPA excretion was lower than in inflammatory bowel disease. Our results show that the urinary excretion of DTPA is a simple test that measures accurately the degree of activity of inflammatory bowel disease. The test is useful in Crohn's disease as well as in ulcerative colitis, and detects intestinal permeability abnormalities even in clinical remission. Significantly lower excretions are found in other intestinal diseases. The test may be recommended as a screening test for use in clinical practice.