Sclerotherapy is a form of treatment for protruding or dilated hemorrhoidal veins. Basically, the physician would inject a needle into a vein, and then infuse a sclerosing agent. Now, this particular agent will cause scarring within the vein such that the dilated vein gradually shrinks. Now, this is an older form of a hemorrhoidal treatment. Again, it can be performed in the outpatient setting. However, what has to be careful, because it may leave residual scars. In some instances, sometimes these scars can cause ulceration in the region of the hemorrhoidal vein, and/or in some small number of cases, it may have an effect on the anal sphincter, such that a patient may subsequently experience episodes of incontinence or the seepage of stool.