What should I do about my cockatiel?! I think he is sick!?

I have never had this problem before until I switched him to pellets awhile ago. I have noticed that he is having light tanish poop in his droppings and the gooey part has whitish-yellow and light red. I'm really worried. I don't think we have a bird vet here and my mom would probably think he is fine. I'm going to ask her when she gets off of work, but we don't have all that much money. But please tell me if something is wrong with my bird!! I'm really worried. Just now I found a poop that has two stringy poop in it.