From his youth St. Francis was plagued with ill health.  St. Clare was no stranger to sickness, spending the last twenty-eight years of her life as a chronic invalid.  Both understood all too well that

         In illness, man experiences his powerlessness, his limitations, his finitude.
Catechism #1500     

They, too, had to struggle so that their prolonged and painful illnesses did not lead to anguish, self-absorption, (or) even despair. Catechism #1501  Only by faith could they recognize God at work in their sufferings, calling them to something greater and deeper than mere endurance.  The Seraphic saints discovered that

By His Passion and death on the Cross, 
Christ has given a new meaning to suffering:
it can henceforth configure us to Him
and unite us with His redemptive Passion.
Catechism #1505

            Thus physical weakness and limitation, pain, fatigue and discomfort were transformed for them into opportunities to allow Jesus to associate them with His own life of poverty and service.
 Catechism #1506 

 While there were times when both Francis and Clare were granted the power to heal others of their infirmities, they knew firsthand that even the most intense prayers do not always obtain the healing of all illnesses.

Catechism #1508

Like St. Paul , they learned from the Lord that
“My grace is sufficient for you, for My power is made perfect in weakness.” 
Catechism #1508

             May their prayers help us to approach suffering with a spirit of unlimited trust in the Divine Physician whom Himself took our infirmities and bore our diseases.
Is. 53:4