HEMORRHOIDS - PATHOLOGY, PATHOPHYSIOLOGY AND ETIOLOGY

Haemorrhoidal disease is the consequence of distal displacement of the anal cushions, which are normal structures with an important role in continence. The causes of haemorrhoidal disease are unknown; constipat ion and abnormal bowel habit are commonly blamed despite largely contr ary evidence. The most consistently demonstrated physiological abnorma lity is an increased maximum resting anal pressure. Most evidence poin ts to this being a secondary phenomenon rather than the cause of haemo rrhoidal disease. Among the many unexplored areas are the function of the longitudinal muscle in relation to haemorrhoidal disease, the desc ription and pharmacological responsiveness of the anal subepithelial m uscle, and the clinical role of specific pharmacological agents that m ight reverse some of the observed physiological changes.