Outpatient sections in government hospitals functioned with house surgeons manning them, official sources said.
The demands included notification on the service and wage conditions of doctors and increase in stipends to postgraduate students on par with their counterparts at national level.
Kerala Government Medical Officers Association (KGMOA) has begun a hunger strike in front of the Secretariat since the past two days against the government's refusal to implement the long-pending demands.
Health Minister V S Shivakumar has said the government would strongly face the agitation.
There were vacancies of over 1,500 doctors in taluk hospitals which were not being filled, putting pressure on doctors to work longer hours, she said.