I am slowly transitioning into a vegan lifestyle and starting with vegetarianism. I have found that, since i have started eating this way, my stomach has been so unhappy. I only eat dairy once a day so I'm not consuming more than usual. I have found that lentils, beans and many vegetables upset me, but I thought this would get better if i stopped eating meat - it has gotten worse. It got so bad once that i thought id magically gotten pregnant and was having contractions! haha (not really just trying to explain the pain).
I would be so grateful for advice as i do not want to eat meat but this stomach pain is awful and I want to ensure that I am getting all the nutrients that my body needs.
It's great to hear that you want to eat more plant based, and great that you are doing a transition as its usually easier that way :)
You aren't alone with the stomach pain due to eating beans, many people can feel that discomfort (ive never actually had a problem with it, but i think thats because ive grown up eating beans and lentils so my body has adapted.). The pain and stomach discomfort is because beans have fiber and they have a type of carobhydrate chain/binding that the body doesnt have enzymes to break down, so the beans go to your large intestine where they become prebiotics for your gut bacteria and that leads to gasbuilding in your intestine and leads to flatulence and bloating and pain. When you first begin eating alot of beans this is definitely an inconvenience for many and can make them unwilling to continue eating beans, however your body CAN and does adapt if you keep eating them. After a while of regular consumption of beans your stomach wont bloat as much and you wont get any cramps (or less).
My best suggestion is to slowly increase your fiber intake or your beans and lentils intake. Maybe just add some beans to your salad or to your lunches and dinners, and vary which beans you eat as well as different lentils. It can be very hard on your stomach if you go from low or moderate fiber intake to suddenly alot of fiber. Fiber is beneficial and good for your body, but too much will leave you in pain!!! But also some people are very sensitive to fiber and need to eat a low fiber diet so that their stomach doesnt go crazy.
Other tips are to add baking soda or vinegar to water if you are soaking the beans over night, as that can help break down/leach out some of the undigestable starches. And also to change the water before you cook them, as well as making sure to rinse the beans properly before and after you have cooked them. Also make sure that the beans are cooked poroperly, this is both for digestive reasons as well as wanting to get rid of the antinutritionell substances and/or bakteria/toxins on the beans. Also i think you can get digestive enzymes which might help, if you really want to eat beans but feel that your body is taking a long time to adapt.