MVP with trivial or mild regurgitation is a pretty common finding. With a standard workup (echo, EKG, physical), your cardiologist should be able to tell you if you are at any increased risk for endocarditis. I am not a doctor, but based on what you have posted, it doesn't appear that you should be too concerned about endocarditis. Of course, it is always best to check with your own doctor. I've had MVP and regurg. for nearly 30 years that I know of, maybe longer. I take antibiotics prior to dental procedures and for certain invasive procedures. Although endocarditis can occur in any of us, your findings do not generally place you among those with a higher risk of developing endocarditis.
If it makes you more comfortable, check with your internist about managing the hemmorhoid and try not to worry about endocarditis.
Here is a link from the Cleveland Clinic. These guidelines were updated in 1997 and are currently under revision again. But, here is the basis for the antibiotics.
http://www.clevelandclinicmeded.com/diseasemanagement/infectiousdisease/prophylaxis/prophylaxis.htm
If you go to American Heart Association you will find that they just updated the guideline and antibiotic prophylaxis is no longer necessary for MVP or mitral regurge. only people with serious heart problems are being advised to have SBE.