This what the leaves looked like when I first got it

Hi I purchased a Adenium from Home depot a couple months ago and I've noticed the stem, certain parts of it is yellow. It feels hard to the touch. I have repotted it and checked the roots, there is no rot or soft spots. The leaves were a litte yellow when I purchased it so I trim some of the stems off. It is putting out alot of new growth where I had trim. The stems that I did not trim has flower buds on them. I have fertilize it with water soluable fertilizer half strength. I've only been watering it when the soil feels alitte dry. Has anyone have this problem? Is this normal? Am I worrying too much? I really love this plant and I hope it's not slowly dieing from the inside *sigh*