My husband first had pain on his right side of his stomach (mid to lower) for a few days now the right side of his back his hurt

Lower right abdominal pains: This kind of pain occurs in the right side. It may spread to left side or back side. It is caused by appendicitis, bowel cancer, Crohn’s disease, constipation, diverticulitis, hernia, intussusception, lymphoma, kidney stones, psoas abscess, pyelonephritis, ulcerative colitis, sickle cell disease etc.

Near the surface maybe a pulled muscle, tendon tear or other injury problem.

Might be a good idea for him to see a doctor.