Question
I have always had good luck with my orchids; however, this one was doing so well with a new flower stem growth, but lately the leaves are shriveling as well as the flower stem buds. I have it in orchid bark and water every week.  I'm at a loss.

Answer
Hopefully you have been using an orchid potting mix and not straight fir bark.  Fir bark alone may result in a potting mix that stays too dry and is difficult to wet.  On the other hand, phalaenopsis orchids need an annual repotting after each flowering to keep the mix fresh and  allow air and water to pass freely through.  Orchid potting mix tend to decay over time.  When that happens, the mix stays wet too long and consists of finer particles which reduce the flow of air to the roots.  That sets up a chain reaction in which the roots begin to rot.  Root rot means nutrient flow to leaves and buds is reduced and that is seen as shriveling, If you have not repotted in the past year, you should obtain a bag of fir bark based orchid potting mix. Soak a portion of the potting mix before use.  While it is soaking, unpot your plant and rinse some of the old potting mix from  the roots (it's ok to leave some on).  If you find any collapsed, mushy roots, those are dead and should be removed prior to repotting. If you have root rot, the part of the plant served by those roots will not recover and the fresh potting mix will allow you to grow new roots and leaves. Those leaves and buds that are now shriveling, may not recover,  Be sure you have a pot that allows for good drainage and do not let the pot sit in water.  If your potting mix is in good condition, there may be other explanation, but I find that a degraded potting mix is usually the culprit in situations such as you describe.