What illness did Amir Shakkar have, and what was Sai Baba's prescribed treatment for him?

As described in Chapter 22, Amir Shakkar was afflicted with rheumatism and approached Sai Baba for a remedy to be delivered from his sorrow. Instead of a physical medicine, Baba's treatment was a command: Amir was to stay steadily in the Chavadi. The text explicitly states that Baba's medicine was simply His word. Despite the Chavadi's dilapidated and unhealthy conditions, Amir was to reside there, which was the unconventional cure prescribed by Baba for his ailment.