Hi there, I have a tank full of fish, and we had a couple of Khuli Loach fish in there as well.
Recently, we found a Khuli Loach (could hardly recognize it!) dead. It was quite large, like it was swollen, and it was a bright red. (it was like a straight prawn) - was this a normal death of a loach, or was it a disease?

soz i put bleach in the tank

Loaches are more susceptible to diseases than regular tropical fish. They are scaleless and as such do not have the defensive layer. They get ick easily and other diseases before tetras or others seem to get it. Do not use bleach to clean your tank. http://zoocrewkids.blogspot.com/