Well, take this new information to the dr for sure. If you are consuming less than 1100 calories per day (taking your wt into consideration, too) your body may think it is starving and turning everything into fat stores. You didn't say what the colonoscopy was for or what it showed...an illness may cause these symptoms.
If your dr clears you for a diet and exercise program- we have great ones on BeachBody. www.beachbodycoach.com/linnlmt They are practical, safe and affordable.
Plus, we would need a few details on your foods that you eat now to make a more educated guess as to whats going on. also- be careful- none of us are allowed to diagnose your symptoms. Feel free to check out my site, I'm a Coach with BB, and also a licensed massage therapist.
Let me know how you do- I care. LinnLMT