Oh boy...I do not miss those days. TJ had the same problem. I was at the Vet every other day. Those noises, so loud. TJ wouldn't eat, he would just lay around sometimes all day 10 hours. Finally, he would poop, the first 1/2 inch would be 'normal' poop, then yucky, smelly, yucky, orangish/yellowish PURE GLOBS of MUCUS...then once that was out, he'd run to the food and he was fine, till the next day.
We did everything you can think of, Medrozone (sp?) NEVER WORKED. Then we switched him to a special diet (Duck and Potato) - this made it better, but not gone for good. Then we did blood work. We found out that TJ had a bateria overgrowth somewhere in his small intestines. The Vet suggested Tylan Powder. This was the ticket! I had to give him a tiny bit of the Tylan powder everday for about 9 months or so. TJ has NO MORE Mucus poops. No more Tylan (for now) and he can tolerate eating anything!
Do a 'search' here on yorkietalk for Tylan. You will find many of my stories
Ask your Vet about Tylan powder!