Hi, Welcome to healthcare magic! You have not mentioned for how long you have been having loose stools. Since the management of acute and chronic diarrhea is different, I would like to know how long you have been having diarrhea. But since you have mentioned that you have done all basic tests done, I presume you have chronic diarrhea. Since you have night time diarrhea also, further evaluation is necessary. You need test like upper GI endoscopy with duodenal biopsy and colonoscopy for further evaluation.