Introduction: Perianal discharge is a cause of significant morbidity, often requiring repeated surgical procedures due to tendency to recur. Anal abscesses and perianal fistula being the most common causes. Our main objective was to elucidate the cause and epidemiology of patients presenting with perianal discharge in the South Indian population. To illustrate the spectrum of MRI features in patients presenting with perianal discharge and to study MRI pattern of perianal fistula.
Materials and Method: Prospective descriptive study. 58 patients of both sex and age ranging from 20 to 70 years who were referred for MRI fistulogram with complaints of perianal discharge were selected for study and analyzed.
Result: In our study, we found that perianal discharge was common in young and middle-aged populations. The highest incidence was noted in the age group of 20-30 years. Perianal discharge was seen to affect males more females in an almost ~ 2: 1 ratio. In our study, we found various causes of perianal discharge on MRI. Perianal fistulas forming a major bulk of cases (77%). The rest of the causes included perianal sinuses (12%), perianal abscesses (7%), anal fissure (1.7%) and pilonidal sinus (1.7%). According to St. James University Hospital Criteria, we found Grade 1 perianal fistulas were the most common type, followed by Grade 2. We found 13 cases (29%) to have secondary branches or ramifications. We found 12 cases (27%) to have horseshoe or intersphincteric abscesses.
Conclusion: Perianal fistulas are the most common cause of the perianal discharge. Perianal sinuses, perineal abscesses and pilonidal sinuses constitute an insignificant group. Almost one-third of perianal fistula cases are noted having secondary branches or association with abscesses, which are better elucidated on MRI. Thus, avoiding the need for repeated surgeries.