IBS is the most common GI functional disorder but some patients don’t fit completely with its diagnostic criteria. It seems that a subset of these patients with bloating and incomplete defecation located on the boundary of IBS and IBD and constitute a distinct group as irritable colitis.

Keywords: bloating, incomplete defecation, colitis

IBD, inflammatory bowel disease; IBS, irritable bowel syndrome

In gastrointestinal outpatient clinics, more than one third of patients have functional gastrointestinal disorders, IBS being the most common diagnosis.¹ But in clinical practice every gastroenterologist has challenged tedious cases with multiple abdominal complains who don’t fit to any clinical group. A subset of these patients complain of bloating, incomplete defecation, tenesmus and mucous discharge. Most often these patients are wondering between different physicians and specialties including General physicians, Internists, gastroenterologists and even complementary and alternative medicine with unsatisfactory results. Some physicians classify them as irritable bowel syndrome (IBS) based on Rome criteria^2-4 but these criteria are not suit for all of patients especially those with complain of bloating because they have no abdominal pain as cardinal symptom of IBS^2,5 or just complain of nonspecific abdominal discomfort. The management of these patients based on diagnosis of IBS usually result in disappointing symptoms relief and they often seek another physician with hope of definite cure.

Some other physicians diagnose them as bacterial overgrowth and try a course of antibiotics⁶ while the others refer them as microscopic or indeterminate colitis.^7,8 Although IBS have overlap with IBD and microscopic colitis,⁹ these group of patients don’t complain of diarrhea as a major symptom and in biopsy from colonic mucosa, the pathologic features of IBD or microscopic colitis don’t exist. One other clinical possibility about these patients is food allergy specially non-gluten sensitive enteropathy¹⁰ which deserve a detailed investigation of patients’ background for any possible history of food allergy.

In our research center, we have performed a clinical trial on these patients (Alavinejad et al. (in press)) and included patients after achieving a normal colonoscopy with multiple random biopsies and also negative celiac serology. We achieved a dramatic response with a brief course of low dose 5-ASA and Bismuth subcitrate. The rate of symptoms relief among participants was about 75% and long lasting. It seems that these group of patients constitute a distinct group with chief complain of incomplete defecation and bloating and located on the boundary between IBD and IBS. We nominated them as irritable colitis (combination of irritable bowel syndrome and inflammatory colitis).

This issue deserves to be further clarified with future studies especially in the field of immunology and HLA typing and small intestine microbiota investigation by culture and chromatography. It is presumed that with further investigation, a clinical scoring system introduce based on presence or absence of their major symptoms (incomplete defecation, bloating) and assist us to better classify these patients which seems to be located on the edge between IBD and IBS.

It seems that a subset of patients with chief complains of incomplete defecation and bloating constitute a distinct group and located on the boundary between IBD and IBS. This category, nominated as irritable colitis, need to be further illustrated with further investigation.

None.

Author declares that there is no conflict of interest.

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