How is inflammation a symptom and not the problem? Tendonitis is just inflammation of a tendon. Once the inflammation is gone the problem (tendonitis) is gone. Now if he continues to do what caused it in the first place it might come back but inflammation is the problem. The orthopedic I saw told me to stretch, rest, and use ice/heat to get rid of it. Although if it's bad enough your only options will be steroid injections or surgery.
Oh, friends. Let's talk about this. Tendonitis is not just inflammation. The inflammation is due to intrinsic or extrinsic factors within the muscle or tendon. If the tendon is stretched vigorously or is asked to transduce more force than it is able, there is damage at the junction. Inflammation is present to address the actual damage to the area.
You do need to lightly stretch (VERY lightly from day 1 to about 7-10), ice it, etc. At a certain point, inflammation CAN hinder healing due to stagnation of blood flow edema (limiting joint ROM). Addressing the inflammation too early will actually delay healing. The inflammation isn't just there for kicks - it's there to promote healing, especially early on.
If it really is tendonitis and the cause is just overuse or strain, then getting rid of the inflammation and resting it is the fix. There's nothing else to fix.
I'm not saying this to be mean, but talking about things outside of your scope is misleading to people who have no idea. Tendonitis can be caused by so many things - instrinsic factors such as muscle tightness, bony protrusions, synovial sheath length; extrinsic factors such as activities, force generation, speed of muscle loading. It can be caused by poor biomechanics or just over-use. However, the inflammation will go away in 5-7 days typically. The injury will remain until it's done healing, which will take more than 8 weeks. Tissue damage is what must be addressed - not inflammation. Inflammation, as I said, is ONLY a symptom. The tissue damage is the true issue that must be rehabilitated.
<- Physical therapy student, been going to school for 5 years in total for this.