Suggest Treatment For A Painful Lump On The Rectum

Okay so I ve been having pains and burning in my rectum since about February and it hurts so bad when I go to the bathroom it s unbearable like a horrible burning feeling, and I feel like a lump in my rectum, even though I feel the pain all the time, it s not as bad as sometimes, when it does burn real bad my stomach is always hurting , I went to the doctor and he did a exam with his finger and said I had 3 internal hemriods but they never bleed and my stomach hurts alot. I took some Pepahartion h suppositories and when I went to insert them it felt like my rectum was swollen pretty bad inside, I m a 23 year old male and weighs around 270.and I don t exactly eat healthy. Does this sound like hemriods to you? Or something more serious like cancer