Updated: Cricket commentator Mark Nicholas back in hospital

Cricket commentator Mark Nicholas is back in hospital. Photo / File

Mark Nicholas' illness has forced the Channel Nine cricket commentator to take leave.

Nicholas left the MCG in an ambulance with stomach pain on the first day of the Boxing Day Test.

After resting on Day Two, he returned to work on Wednesday, but fell ill again and had to return to hospital.

"Mark is taking leave to resolve his health issues," a Nine spokesperson said, this morning.

"He wants to thank everyone again for their kind wishes and continued support."

It's understood Nicholas struggled to get through a tea-time segment with Pakistan great Wasim Akram, before again succumbing to severe abdominal-related pain in the breakout area off air.

He was sweating profusely and later complained of headaches.

Australian team doctor Peter Brukner was immediately called to assist Nicholas, before paramedics were called to stretcher the 59-year-old to a waiting ambulance and then to hospital for further testing.

Nicholas left the Melbourne Cricket Ground in agony, but conscious and breathing.

The latest incident wasn't as dramatic as the events on Boxing Day, when Nicholas was rushed to hospital in a frightful sweat.

However, there are concerns that the problem hasn't been fully diagnosed and that Nicholas suffered a reoccurrence just two days later.