Bee Gees Singer Smiling in London After Hospital Emergency

10/25/2011 9:12 AM PDT

Two weeks after being hospitalized for severe abdominal pain and inflammation of the colon, Bee Gees co-founder Robin Gibb was spotted leaving a television studio in London on Monday.

The 61-year-old -- who's been battling a crippling stomach condition -- appeared on a local TV show to promote a charity single.

Gibb's rep had described the medical situation as a "difficult time" ... but judging by the smile on Robin's face, he seems to be in good spirits.