What Causes Chronic Constipation Long After Having A Colonoscopy?

I usually have normal bowel movements, once a day. 4 days ago, I had a 24 hour period of cramps and very loose bowel movements for no known reason. That stopped after the 24 hour period. I have , now not had a bowel movement of any kind for 3 days. I feel fine with no pain whatsoever. I had my last colon oscopy (sp?) 4 years ago. I had no polyps and very few diverticula, and the gastoenterologist said everything was fine, That was my third one since I was fifty. I am now 78, I have no genetic history of colon cancer, Is it normal to not have a bowel movement for this many days when before the 24 hour episode of loose stools and gas I had normal bowel movements almost every day. I have no pain and I feel completely normal other wise and I try to walk a little each day to exercise?