Aetiology of thrombosed external haemorrhoids: a questionnaire study

We conducted a questionnaire study of individuals with and without TEH. Aetiology was studied by comparison of answers to a questionnaire given to individuals with and without TEH concerning demography, history, and published aetiologic hypotheses. Participants were evaluated consecutively at our institution from March 2004 through August 2005.One hundred forty-eight individuals were enrolled, including 72 patients with TEH and 76 individuals without TEH but with alternative diagnoses, such as a screening colonoscopy or colonic polyps. Out of 38 possible aetiologic factors evaluated, 20 showed no significant bivariate correlation to TEH and were no longer traced, and 16 factors showed a significant bivariate relationship to TEH. By multivariate analysis, six independent variables were found to predict TEH correctly in 79.1% of cases: age of 46 years or younger, use of excessive physical effort, and use of dry toilet paper combined with wet cleaning methods after defaecation were associated with a significantly higher risk of developing TEH; use of bathtub, use of the shower, and genital cleaning before sleep at least once a week were associated with a significantly lower risk of developing TEH.Six hypotheses on the causes of TEH have a high probability of being correct and should be considered in future studies on aetiology, prophylaxis, and therapy of TEH.Although anorectal disorders are common [1-4] no data exist regarding the prevalence, incidence and aetiology of thrombosed external haemorrhoids (TEH) [3,5-9]. Common clinical presentations are as a single external pile (figure 1) or as circular thrombosis of external haemorrhoids (figure 2). A single TEH is characterized by acutely evolving, painful, circumscribed perianal swelling of a dark colour occasionally with bleeding (figure 3), and a perforating clot [2,5,6,10,11] (figure 4).We limited our study to single lesions using Hancock's definition of "an acute localised thrombosis which may affect the external