What Causes Prolonged Periods Delay, Abdominal Cramps And Bloating?

Hi, I am 55 years old, have not had a menstural cycle since January. My stomach feels crampy if my cycle is about to begin, but nothing ever happens. My stomach also feels bloated at times. I have also noticed a change in bowel habits. I developed a hemorrhoid problem after the birth of our first child, but it has gotten worse lately. I had a colonoscopy about 4 years ago and one polyp was found. I was told to come back in 5 years. I watch what I eat but have put on weight in the past two years. I really just want my stomach/digestive system to feel better but I am also concerned that my problem could be colon or ovarian cancer.