Complex sentence: A stomach ailment that Rizzo had from 1939 continued to cause severe abdominal pain, despite extensive medical treatment, until January 18,1943, when she claimed that she woke up with no pain.
Split into simpler sentences: A stomach ailment that Rizzo had from 1939 continued to cause severe abdominal pain, despite extensive medical treatment. On January 18,1943, Rizzo declared that she woke up with no pain.