My 16 year old tuxedo, Charley, has megacolon. He also has diabetes and asthma, so it's been difficult to manage his health. But in regards to megacolon, he has been doing well lately with a combination of Cisapride and Miralax. I do have to adjust the doses from time to time. I have read about other cats here who have been on Cisapride so I felt it important to mention that Cisapride really increased my cats hunger. Since hes been on Cisapride, at times he will eat normally, but at others he will meow incessantly for food and when I bring the bag of food out he will go bonkers with meowing and purring - like he's been starved for a week! Just a heads up for anyone who may be wondering why their megacolon cat seems hungry all the time. Cisapride will cause it!