Hello! Thank you for the query. Such lump is a hemorrhoid most likely. Due to enlarged veins in the rectal area, a lump appears. If its large enough, can be visible outside the anus (like at your case). The main reason of hemorrhoids is bad diet (low fiber intake, fatty foods intake) and lack of physical activity. Very often it can appear during pregnancy. To improve hemorrhoid condition I suggest you to improve your diet (fiber rich products), use hemorrhoids suppositories for few days and have sitz baths with Oak Bark twice a day for 5 days. This should improve its condition, but it wont make it go away. The only permanent solution is surgery. Hope this will help. Regards.