I also have loose stools daily. Weight loss in the face of adequate calories is a sign that a serious pursuit of a serious illnesses must commence. There is no sense in tiptoeing around the cancer issue. Cancer is not the only cause of weight loss, and it might not be the most common cause. It is the most dangerous cause, and the doctor must search for it.
Malabsorption is another frequent cause.
That might be your trouble, for malabsorption frequently leads to diarrhea. The malabsorption illnesses are many. However, a few, somewhat simple tests can determine if the digestive tract is not breaking down food for absorption. Once that fact is established, the doctor has more latitude in a less harried rush to find a cause than the threat of cancer demands. Weight loss can come about from causes not related to the digestive tract.