I've done some search to fix the digestive issu :

• You cooked them without the skin.
• With the skin, they should not be cooked too long , they must have a taste of hazelnut not artichoke.
• Lactic acid fermentation is also said to solve the issue.
• Some said you have to put a potato or some sage leafs in the cooking water.
• On last resort you can always mix with something else and with time you'll grow a bacterial flaura that's help digest it.