HEALTH PROBLEM ! COLON ? INTESTINES ? POOP ?

what does it mean when for the past 3 days you are trying to poop but it takes 20+ minutes to get the poop to come down and out ? and then today only a little bit , about 32 inches in diameter , comes down and out but the rest never comes down OR out ?Pleaseeee help me this is serious tell me what it means ANYTHIN HELPS !!!