-- Database schema
| Ingredient : ingredient_id [ INTEGER ] primary_key , category [ TEXT ] , name [ TEXT ] , plural [ TEXT ] | Recipe : recipe_id [ INTEGER ] primary_key , title [ TEXT ] , subtitle [ TEXT ] , servings [ INTEGER ] , yield_unit [ TEXT ] , prep_min [ INTEGER ] , cook_min [ INTEGER ] , stnd_min [ INTEGER ] , source [ TEXT ] , intro [ TEXT ] , directions [ TEXT ] | Nutrition : recipe_id [ INTEGER ] primary_key Nutrition.recipe_id = Recipe.recipe_id , protein [ REAL ] , carbo [ REAL ] , alcohol [ REAL ] , total_fat [ REAL ] , sat_fat [ REAL ] , cholestrl [ REAL ] , sodium [ REAL ] , iron [ REAL ] , vitamin_c [ REAL ] , vitamin_a [ REAL ] , fiber [ REAL ] , pcnt_cal_carb [ REAL ] , pcnt_cal_fat [ REAL ] , pcnt_cal_prot [ REAL ] , calories [ REAL ] | Quantity : quantity_id [ INTEGER ] primary_key , recipe_id [ INTEGER ] Quantity.recipe_id = Recipe.recipe_id , ingredient_id [ INTEGER ] Quantity.ingredient_id = Ingredient.ingredient_id , max_qty [ REAL ] , min_qty [ REAL ] , unit [ TEXT ] , preparation [ TEXT ] , optional [ TEXT ] |
-- -- Please list the titles of all the recipes that may lead to constipation, feeling sick or stomach pain.

SELECT T1.title FROM Recipe AS T1 INNER JOIN Nutrition AS T2 ON T1.recipe_id = T2.recipe_id WHERE T2.iron > 20;