Mimics of Inflammatory Bowel Disease in Clinical Practice

Mayank Jain

doi:10.7869/tg.610

There are several conditions that mimic inflammatory bowel disease (IBD) because of location, symptoms, or appearance on endoscopy, imaging and histology. Consideration of alternative diagnosis is important when conventional therapy does not work or worsens the symptoms. In Indian setting, the diagnosis of IBD is further complicated by the presence of numerous gastrointestinal infections which may mimic IBD. The present study is a retrospective analysis of cases where IBD mimics were diagnosed.

Case Report

Over a nine year period, 104 cases with suspected IBD were seen by the author. Of these, 88 were suspected as ulcerative colitis (UC) and the remaining as Crohn’s disease (CD). Diagnosis of IBD was suspected if 2 or more of the following symptoms were present- fever, weight loss, abdominal pain, chronic mucoid or bloody diarrhoea, subacute intestinal obstruction with or without right iliac fossa mass.¹ The diagnosis was confirmed using radiological investigations (ultrasound, computed tomography), colonoscopy evaluation and histopathology. Based on histology, and re-evaluation in cases with non-response, the eventual diagnosis was changed in 11 cases. These included 4 cases of suspected ulcerative colitis and 7 cases of suspected Crohn’s disease. Thus, detection of IBD mimics was commoner in those with suspected Crohn’s disease (44% vs. 4.5%, p<0.001).

Infections were commonest mimics and were noted in 6 cases (54.5%). Tuberculosis and amoebic colitis were detected in 3 and 2 cases respectively. Earlier Indian studies have tried to distinguish CD and tuberculosis based on symptoms, endoscopy, histology and imaging.^2,3,4,5 In the present study, 3 patients (median age 24 years, 2 males) presented with abdominal pain, diarrhoea and weight loss. Imaging showed thickening of terminal ileum and ascending colon. Colonoscopy in these cases showed aphthous ulcers in terminal ileum (100%) and few colonic ulcers (2 cases). Ileocaecal valve was normal in all three cases. Histopathological evaluation showed caseating granulomas and features of chronic ileitis. All the patients responded well to anti tubercular therapy. The two cases with amoebic colitis presented with periumblical pain, fever, diarrhoea and weight loss. They were both males with a mean age of 32 years. Imaging showed thickening in terminal ileum and ascending colon. Colonoscopy revealed multiple superficial ulcers in ileum and ascending colon. Histopathology showed acute inflammatory changes with amoebic trophozoites, thereby, confirming the diagnosis. Another interesting case was a 22 year old male patient with HIV infection (CD4 count 345) who presented with bloody diarrhoea and weight loss for 6 months. Imaging showed thickening in rectosigmoid region. Colonoscopy showed deep ulcers in the rectum and sigmoid colon. Biopsies showed dense inflammatory infiltrate. The patient had been started on mesalamine enema with no improvement in symptoms. On reviewing the history, it was noted that he had homosexual behaviour and indulged in unsafe sexual practices. Ig G serological test for Chlamydia trachomatis was positive and diagnosis of lymphogranuloma venereum proctosigmoiditis was made. The patient responded well to treatment with doxycycline 100 mg twice a day for 4 weeks.

Five other cases (45.5%) were diagnosed with rarer diseases based on the clinical profile, histology and response to treatment. (Table 1) Segmental colitis with diverticulosis (SCAD) was noted in one case. This condition is noted among older adults, predominately males. It is usually localized to sigmoid colon, spares the rectum, and often resolves spontaneously without treatment. Rarely, a limited course of therapy with 5-aminosalicylate, corticosteroids, or surgical resection is needed.⁶ Solitary rectal ulcer syndrome is known as the “three lies disease” as it is not always solitary, not always an ulcer and no always rectal in location. It is characterized by fibromuscular obliteration, ulceration, crypt distortion and hyperplasia, splaying of smooth muscle cells and fibrosis of the lamina propria.⁷ Eosinophilic enteritis, Behcet’s disease and NSAID enteropathy are rarer IBD mimics seen in India and reported mainly as case series.

To conclude, IBD mimics are detected in nearly 10% of cases of suspected IBD. They are commoner in CD than UC. Infections are the commonest IBD mimics in Indian scenario. So, beware before making a diagnosis of IBD and always be open to consider the possibility of IBD mimics.

References

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Amarapurkar DN, Patel ND, Rane PS. Diagnosis of Crohn’s disease in India where tuberculosis is widely prevalent. World J Gastroenterol 2008; 14: 741-6

Pratap Mouli V, Munot K, Ananthakrishnan A, Kedia S, Addagalla S, Garg SK et al. Endoscopic and clinical responses to anti-tubercular therapy can differentiate intestinal tuberculosis from Crohn’s disease. Aliment PharmacolTher 2017; 45: 27-36

Schembri J, Bonello J, Christodoulou DK, Katsanos KH, Ellul P. Segmental colitis associated with diverticulosis: is it the coexistence of colonic diverticulosis and inflammatory bowel disease? Ann Gastroenterol. 2017;30(3):257–261.

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