The Role of High-resolution Anorectal Manometry in the Diagnosis of Functional Anorectal Disorders in Patients With Inactive Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic disorders of the gastrointestinal tract associated with debilitating symptoms due to immune mediated enteric inflammation. Western countries have been historically observed that IBD is prevalent and continues to rise, whereas the general impression is that countries in the Middle East (ME) experience a lower incidence of IBD. Incidence rates vary considerably depending on the region. In 2017, Ulcerative Colitis (UC) incidence rates ranged from 0.97 to 57.9 per 100,000 in Europe, 8.8 to 23.14 per 100,000 in North America, and 0.15 to 6.5 per 100,000 in Asia and the ME. Nonetheless, recent trends have shown a significant rise in the incidence of IBD in Middle East countries, which were linked to "westernization" in lifestyle, including dietary habits in these countries .

Unfortunately IBD remains incurable .As a result, many patients experience intermittent flares of intestinal inflammation in an unpredictable relapsing-remitting pattern, with recognizable symptoms of increased bowel frequency, bleeding and urgency. While advances in the treatment of IBD in recent decades have increased the likelihood of achieving disease remission and mucosal healing, a significant proportion of patients still present with refractory gastrointestinal symptoms. In this context, there can be considerable overlap between symptoms in active IBD and overlapping coexisting functional gastrointestinal disorders in patients with quiescent disease.

Given the complexity of the normal continence and defecatory mechanism, it is unsurprising that disruption of one or more mechanism as a consequence of IBD can lead to either evacuatory dysfunction or fecal incontinence (FI) and multiple factors are involved in its pathogenesis.

Conventionally, Dyssynergic defecation ( DD) is an acquired behavioral disorder in which coordination is lacking between the pelvic floor/anal sphincter with abdominal muscles at the time of defecation. Among IBD patients, DD may be challenging to identify as it can present atypically with symptoms other than constipation, including urgency, rectal pain, sensation of incomplete evacuation, fecal incontinence, and frequent defecation.

This poses a significant challenge for clinicians, as failure to positively recognize functional disorders in patients without objective evidence of active inflammation, can lead to repeatedly negative and often invasive investigations, increased healthcare utilization, futile and potentially hazardous escalation of IBD therapies, and patient dissatisfaction due to refractory symptoms.