A side effect of the surgery became problematic for Jobs because of his obsession with dieting, his strange bowel habits and fasting since he was a teenager. Because the spleen provides enzymes that help the stomach digest food and absorb nutrients, removing part of it makes it difficult to. Jobs celebrated his thirtieth and fortieth birthdays with Silicon Valley stars and other celebrities. But when he turned fifty in 2005, after returning from cancer surgery, at a surprise party his wife organized.