Not always. There may be a threshold of quantity of the food item one is intolerant of needing to be ingested before symptoms surface, plus quantity may play a significant role in the severity of the symptoms. Unlike those who have a severe allergy to even inhaling tiny particulate matter of foods they are allergic to, those with intolerance to foods may be able to tolerate certain amounts of the offending foods before symptoms show.
There are some symptoms that may be more tolerable than others. Certainly mild fatigue after ingesting an offending food would be more tolerable than even mild diarrhea. Eating an offending food every day that caused mild diarrhea would most likely get the sufferer to more quickly ascertain which food is causing the problem and avoid it while chronic fatigue caused by an offending food may be counter treated with large amounts of caffeine.
Then there are symptoms such as chronic forms of eczema that a dermatologist will not associate with a food intolerance so the eczema is treated as a chronic condition with topical steroid ointments and creams to minimize the flare-ups. A sufferer of food intolerance will soon discover that many medical practitioners only treat symptoms and not causes. This is why many sufferers go for years without diagnosis and resolution.