In a pot over medium heat, add bacon. Cook, stirring regularly until it begins to render fat.
Add onions, garlic and bell peppers. Cook, stirring regularly, until limp and aromatic.
Add chicken breast and cook, stirring occasionally, until lightly browned. Season with salt and pepper to taste.
Add tomatoes and cook, mashing with the back of the spoon, until softened and release juice.
Add broth, barbecue sauce, and red pepper flakes. Stir until combined and bring to a boil.
Add pasta and stir to prevent from sticking together. Lower heat, cover and cook for about 15 minutes or until pasta is cooked but firm to bite. Stir every 5 minutes to prevent pasta from burning and sticking to the pan.
Add cream cheese and stir until melted. Continue to cook for about 2 to 3 minutes or until most of the liquid is absorbed.
Add cheddar cheese and stir just until melted.
Garnish with green onions, and bacon crumbles, if desired. Serve hot.