What kind of helpful diet should a fibromyalgia patient have?

No need special diet: Just a health diet with plenty of fruits and vegetables along with daily exercise is the best advise for living with any chronically painful condition.

Low inflammatory die: I recommend to people that they utilze a low inflammatory diet. The major inflammatory foods are those containing wheat, corn, dairy, soy and eggs. Try removing 1-2 of these for 8 weeks. If helpful look at excluding the others. Add a probiotic if you are experiencing constipation or have a history of yeast infection. It should contain 15-20 billion units, 1/day and 2 if you do not have cramping.

Wishing you well!: Add to dr. Cantieri's list "nightshades" (tomatoes, potatoes, eggplants and peppers) that can also contribute to inflammation; worth exploring if you're sensitive to them. Find a practitioner who does applied kinesiology and get muscle tested for sensitivity to these or other suspicious foods. Also explore emotional and physical triggers.