Why does a lump come out while passing the bowel?

Hello doctor,

Two months back, I had severe constipation, and my stool got stuck. So, I had to put more pressure. I felt my bowels were not emptying, so I spent more time in the toilet. Following that, I had an itchy anus, and I did not think much about it then. After a week, I had severe pain in my anus, and a lump started to come out of the anus when I pass bowels. The lump goes back inside by itself. I visited a local doctor who gave me laxatives and antibiotics. The pain was relieved in two days, and the stool got smoother. But the lump remains, comes out only when I poop, and I do not have any other symptoms. I have no pain or blood. Is it cancer or piles it has not gone away in two months? I do not eat vegetables and fruits, so I had no fiber intake for years. I am currently taking medication for diabetes.