Hi, thanks for sharing your health concerns with HCM!           
If I were your treating Doctor for this case of a lump around anus, I would come up with three possibilities, these include: 
1.     skin or hair 
follicle infection due to some friction injury , worms, fungus, piles, fistula or fissure!
2.     The second possibility is of an 
ischiorectal abscess      3.     The last possibility is of some 
infected cyst or 
benign tumor / tumor like condition like 
rectal polyp or skin tag/papilloma!     
Overall, it is possibly inflammatory and not to worry much about this!
I suggest you to go for stool examination and see a surgeon for a physical examination and some medicines; 
Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. 
Wishing you good health.