Chicago ? Some doctors have started fighting back against ugly Internet reviews by asking patients to abide by what are effectively gag orders that bar them from posting negative comments online.

Physicians are taking action as online ratings services such as Zagat’s and Angie’s List grow in popularity and expand their reviews beyond restaurants and plumbers to include medical care.

“Consumers and patients are hungry for good information” about doctors, but Internet reviews provide just the opposite, contends Dr. Jeffrey Segal, a North Carolina neurosurgeon who has made a business of helping doctors monitor and prevent online criticism.

Some sites “are little more than tabloid journalism without much interest in constructively improving practices,” and their sniping comments can unfairly ruin a doctor’s reputation, Segal said.

Here’s a real, anonymous comment about a doctor from the Web site RateMDs.com:

“Very unhelpful, arrogant, did not listen and cut me off, seemed much too happy to have power (and abuse it!) over suffering people.”

Segal said such postings say nothing about what should really matter to patients — a doctor’s medical skills — and privacy laws and medical ethics prevent doctors from fighting back.

His company, Medical Justice, is based in Greensboro, N.C. For a fee, it provides doctors with a standardized waiver agreement. Patients who sign agree not to post online comments about the doctor, “his expertise and/or treatment.”

Segal’s company advises doctors to have all patients sign the agreements. If a new patient refuses, the doctor might suggest finding another doctor. Segal said he knows of no cases where longtime patients have been turned away for not signing the waivers.