Does yoga work in the bodies of people who have some physical defect like having gallbladder or kidney or spleen removed or a limb missing? Did the teachers ever mention something like that?
Yes indeed, yoga practices do work well even for people with physical challenges. Yoga techniques work primarily with the energy body. Most people, especially as they get older, will have some physical limitations. It is important to adjust how the techniques are done to accommodate any physical challenges and not risk some injury. But the techniques are beneficial for everyone.
When I discuss techniques I am including not only hatha yoga postures but also pranayama (energy control) techniques and meditation techniques. Working with all of these practices will enhance the flow of energy in the body which could possibly have become limited due to an injury or illness. It is helpful to seek the guidance of an experienced hatha yoga teacher (for yoga asanas) or meditation teacher (for meditation and pranayama techniques) for guidance in how to adjust techniques to accommodate your body.