Hi Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern... Yes, liquid diet is a must on the previous day of scheduled colonoscopy. If patient have eaten solid meals then these meals remain in colon of patient. Therefore visualization of colon & lower part of large intestine becomes difficult & it makes colonoscopy of no use in diagnosis of any problems of large intestine. As You have eaten meals like toast, peanut butter, banana, avacados, Turkey, Mac and Cheese. Now you should reschedule your appointment for colonoscopy by consulting your doctor. You should avoid having this in future. Refer to your gastroenterologist Hope this information helps