I have to leave the US because i could not find a job and do not want to be illegal. However i want to come back in a year or two to do my masters, but the problem is  I have some unpaid loans and some credit card debts which will go into collection once im gone. Given the scenario that it does go into collections, will that affect me when i apply for my visa from nepal in a couple of years?

Sorry kgarneharke...that is not called bad debt...that is called accounts payable...it will be bad debt for those credit card companies to whom you will not pay and run away.

 OK well my point being i owe money. Is it an issue?

They can't get your money back not letting you come in. So, probably they will let you come in here, help you find a job and pay your debt. I can say some sweet stuffs like this all day to make somebody happy but i donot wanna do that.
So, if you are thinking what my point is( i bet you are). I don't wanna assume something and explain to you as it is some written facts. I know some of the sajha members love doing that but ......

Conclusion: every situation is unique