Can gastritis cause low grade fever (99.00), body ache and stomach ache?

Absolutely: Keep yourself hydrated with any sort of gatorade or similar substance. Keep to a very bland diet. If it persists for more than a few days you must see a doctor to rule out more serious illness.

Gastritis: Gastritis can cause above symptoms. There are different causes of it including certain medications, intake of alcohol. Helicobater pylori is a bacterial infection that can cause gastritis as well. Need to see a gastroenterologist to confirm the diagnosis and needs prompt treatment as it can result in ulcer and other complications.