Haemorrhoids are enlarged raised veins in the anus or rectum. Common haemorrhoids are often linked to both diarrhoea and constipation. Although the belief that haemorrhoids are caused by constipation has been questioned by researchers, most doctors feel that many haemorrhoids are triggered by the straining that accompanies chronic constipation. Therefore, natural approaches to haemorrhoids sometimes focus on overcoming constipation.