Is the discomfort from gas or from constipation? Two different things. If you feel discomfort soon after you eat greens, it's probably gas. Constipation is more of a larger-picture problem relating to your diet overall.
Lots of greens can be gassy, but spinach is generally not one of them, and also contains magnesium which helps clean you out.
Do you react to all green vegetables? Here are 2 possibilities for your constipation associated with some vegetables:
You could react to FODMAPs, or short-chain fermentable carbohydrates. FODMAPs are found in the following green veggies: broccoli, cabbage, asparagus, artichoke, sugar snap peas, leeks, green onions, okra, avocado, Brussels sprouts and snow peas.
You could be sensitive to natural food chemicals, such as amines, glutates and salicylates. These compounds are naturally found in the following green vegetables: avocado, green bell peppers, choy sum, green olives, pickled vegetables, spinach, broccoli, alfalfa, artichoke, cucumber (peel), endive, spring mix lettuce, fennel, snow pea sprouts, watercress, zucchini (peel) and herbs and spices (basil, parsley, mint).
Your best bet is to consume low-FODMAP and low food chemical green vegetables to see if you tolerate them well. Try iceberg lettuce, green beans, peeled cucumber, peeled zucchini, chives and other low-FODMAP and low food chemical non-green vegetables, such as carrot and squash.
If things get better, you can challenge yourself to each FODMAP- and food chemical-containing green vegetables to assess your individual tolerance.
Good luck! :)
More and more people seem to say that veggies cause constipation. It happened to me too, but I don't believe the vegetables caused this, I believe you either have underlying problems (SIBO etc.) or need more animal fat.
Something that helped me tremendously (and still does), is eating a tablespoon of gelatin every single day...
...and here I was thinking I had a weird contrary digestive system. Conventional wisdom preaches how good the fiber in veg is for moving stuff out, but If I'm not eating enough fat I get the exact opposite result.
My 2 year old has had constipation issues pretty much her whole life (well once we managed to rid her of her explosive, bloody diarrhea after figuring out she had a dairy and soy allergy - sorry if TMI!) Switching to paleo helped both mine and my husband's bowel issues (each of us having opposite bowel issues) but it hadn't really helped my daughter until we figured out this - she needed more FAT! That's what makes your poop slide through your colon.
For us, after a lifetime of eating high-carb and low-fat, when we went paleo we didn't even realize how low fat we were still eating because it had become such a habit. But now I make sure my daughter get's lots of healthy fats in each meal and he poops are wonderful!
I'd like to add that the 'fat-to-help-with-constipation solution' is difficult to find much literature on, and I'm guessing it's because of our society's fear of fat. They always say to increase fibre, but that's for someone who probably has next to no fibre in their diet due to eating nothing but refined white flour products.
Additionally you have a bile problem, so your liver is compromised.
Start Coconut oil, Magnesium Citrate, and Probiotics. Lay off the greens for a while ( 3 - 6 weeks ) and try them after that time