2 Yrs Ago I Had Colposcopy With 2 Benign Polyps.

2 yrs ago I had colposcopy with 2 benign polyps. Had change in bowels & abdominal pain everyday. My PCP recommended a new GI Doctor. Had another colonoscopy last week. Had 10 4-6 mm polyps in sigmoid colon, in the cecum 25 cm proximal to anus, congested mucosa at 20 cm proximal to the anus. Diverticulosis in the sigmoid colon. I thought polyps were slow growing therefore colonoscopies were only needed 5-10 years. Should I be concerned & what would cause all that in less than 2 years?