Randi, I too am on Fibersource HN and dont have any unusual problem with mucous from it. In my case I have found that dry mouth and throat make it very difficult to clear the throat so swish and spitting a little water helps (I cannot swallow). Using decongestants is a mixed bag - it can reduce the mucous but drys out the throat. That seems like a lot of food all at once - I only take 1 1/2 containers per feeding (but I use the bolus method). With a pump, you might talk to the dietician about reducing the flow rate a little. as others have said, hydration is very important here as well.