What is the treatment for fructose intolerance?

Treatment involves reducing the consumption of foods high in fructose, so choosing fruits and vegetables known to be lower in fructose content. We all have ability to absorb some fructose, so it does not need to be avoided strictly. It is only when we have excess plus we have a sensitivity to the gas and other products the bowel flora produce in the large intestine (and therefore have symptoms of IBS) that we need to restrict the amounts.

Like most dietary intolerances, the best method to alleviate fructose malabsorption symptoms (such as bloating and excess flatulence) is to follow a low-fructose diet.
Fructose is the natural sugar found in fruits, along with being in high concentrations in honey, high-fructose corn syrup and sugar snap peas. Not all fruits though need to be avoided, just those that have more fructose than glucose in them, as glucose helps fructose absorption in the gut. Some examples of fruits needed to be avoided by those with fructose malabsorption include apples, pears, mangoes, watermelon, peaches, dried fruit and fruit juices.

To add to the great responses above I would also like to add that fructose can also be present as a chain of fructose sugar units (called fructans). 

If you have some form of Irritiable Bowel Syndrome (IBS) combined with Fructose Intolerance, it would highly advised to also avoid fructans as well as galactans for a period of time. Sources of fructans include wheat & rye eaten in large amounts (eg wheat based breads, pasta, cous cous, crackers, biscuits), certain vegetables (eg. broccoli, cabbage, garlic, onions), legumes and a few others.

However when cutting out certain food groups it is important to see an Accredited Practising Dietitian as they will be able to make sure you are still having a balanced diet choosing other suitable alternatives. Eliminating certain foods should only be temporary and your Dietitian should then be able to do challenges to test tolerances to ensure maximum variety in your diet.

The low FODMAP diet will help manage symptoms if it is excess fructose and/or other FODMAPs that are the triggers for your gut/bowel symptoms. It is important to go through this process with the guidance of a dietitian experienced in this area as there is a lot of misinformation on the internet and even handed out by doctors (often as old information). If the diet does help, you then need to go through a challenge process to work out which FODMAPs are the issue and how much you can tolerate. You should not need to completely avoid any healthy foods long term. 
If the low FODMAP approach does not bring symptom relief, and your diet is otherwise healthy, you may have other intolerances.

You need to discern betwen fructose intolerance and fructose malabsorption. 
If you are fructose malabsorbent then you will want to be aware of high fructose foods and stay away from them, a good rule of thumb is the greener the vegetable the less fructose it contains, also be aware that wheat contains fructose so you may find that reducing wheat in your diet helps alot. When eating out you'll find that it is difficult to find foods without onion or garlic so make sure you ask. 
If however you have hereditary fructose intolerance (HFI) you will most likely have an issue with fructose and sucrose (a disaccharide containing fructose) ie. cane sugar. This means that you will also want to manage the level of purines in your diet too as fructose intolerant individuals are more prone to other issues such as gout. The better care you take of yourself now the less damage you will do in the long run so make sure you do your research and know your stuff!  
I am personally affected by HFI and I know that there is very little information available on the topic. I do intend to create a website for people with these issues in the near future, in the meantime ifyou have any questions feel free to contact me.