i presume that they have checked stool studies
I am two years out from transplant, I take so many different kinds of meds, that each day is a surprise as to what the color, consistency, amount will be. Brown, green, lime, clay-like, pink, all kinds of beautiful colors. Mostly pastels though.
i do not think that the loose bowel movements are directly related to the transplant itself. they could be from the medications such as mycophenolate or ursodiol. sometimes certain infections can also contribute. If the liver tests are OK, then the loose bowel movements are not from the liver.