I can help with this since I've had colon cancer and have read just about everything there is to read for almost 6 years now.
There is colon, rectal and anal cancer. There's roids and fissures.
After your first experience, the lump did NOT go away. It went back inside. External roids go back inside most of the time. It most probably was inflamed but not filled with blood. If they are clogged with a clot or dried blood, they will either hang out or have to be gently pushed inside. If they start to throb, you can see the doctor to possibly get some prescription steroid roid cream. Prep H really doesn't help roids. It coats them and can shrink the skin but roids are varicose veins in the rectal area.
Hot sitz baths, no straining, alleviate any constipation, don't sit on the toilet for a long time and use something like KY Jelly on the roid to help it go back inside.
If you are a homosexual male or a female with multiple partners and HPV you might asked to be checked for anal cancer which usually presents as a sore (ulcer) lump on the anus. This is NOT colon cancer and is highly curable IF you take treatment. Farrah Fawcett had anal cancer but refused certain treatments because she would have lost her hair.
My roids never totally go away. They sometimes burst and then shrink but if I'm not very careful, they can get itchy and painful.