Foods to avoid if you have IBS, SIBO, or other digestive issues

Today we are discussing foods to avoid if you have digestive issues. These food groups include, nightshades, brassica vegetables, wheat, and beans and digestive issues such as acid reflux, IBS, SIBO, inflammatory bowel diseases, gas, bloating, constipation, and gallbladder issues.

If you haven’t downloaded the 30 Day Digestion and Microbiome Upgrade Food Plan. I highly recommended it. This is based off of 14 years of patient care and what I have seen consistently help patients reset their digestion without having to indefinitely eliminate food groups. 

Download the 30 Day Digestion and Microbiome Upgrade Food Plan

Many of these foods are health-promoting and can slowly be added back to your eating routine once your digestive system and microbiome are repaired.

So let’s get into why certain food groups can be problematic if we’re trying to heal our digestive system:

Foods to avoid

1. Alkaloids

Nightshade foods include, tomatoes, peppers, eggplants, and potatoes. Nightshades contain alkaloids, such as solanine and capsaicin. These compounds can be irritating to the gastrointestinal tract and promote leaky gut.  Often manifesting as heartburn, acid reflux, or abdominal discomfort.


Some nightshade vegetables, like bell peppers, are high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (aka FODMAPs). These compounds can trigger symptoms in people with irritable bowel syndrome (IBS).

3. Tomatoes

The acidity of tomatoes and tomato pastes are often instigators of heartburn or acid reflux. Tomatoes also can trigger excess histamine release in some people, which manifests as diarrhea, IBS, bloating.

4. Brassica Vegetables

Okay let’s talk about vegetables (I’m a big fan of vegetables) but the following group, because of their ultra tough cell walls, made up of complex carbohydrates like cellulose, are often the cause of bloating for so many, especially those who live fast paced lives.

Collard Greens
Brussels sprouts

These vegetables are often considered highly nutritious or even super foods due to their phytochemcial content, but getting to these nutrients (when eaten raw) can be extremely challenging for those who have digestive issues.

Cooking methods such as steaming, boiling, or roasting can help break down their tough cell walls and make them easier to consume. Also using vinegar and olive oil or animal fats can help with breaking them down and extracting nourishment from these vegetables.

Anecdotally, I had one patient whose CRP was 24 (very high inflammation). She said she thought broccoli was a problem for her. At first I thought, ya I doubt that is the problem. But we removed broccoli which she ate 3-4x per week.

I rechecked her C-reactive protein in a month and it was normal. I had her add it back in and checked two weeks later and her CRP had jumped back up to 20.

She made me a believer. This doesn’t mean broccoli is toxic and we shouldn’t eat it, but it does mean if your body experience isn’t where you want it to be, then it’s worth considering all the foods (yes, even broccoli) coming into your body.

5. Beans and Lentils. 

They contain the heralded gas-producing complex carbohydrates called oligosaccharides that as humans, we can’t fully digest no matter how awesome our digestion is.

Legumes are loaded with anti-nutrients like lectins and phytates, which can interfere with nutrient absorption and cause leaky gut and inflammatory cytokine activation in the digestive tract.

Beans also contain compounds that inhibit digestive enzymes, beans are loaded with amylase and protease inhibitors which decrease the ability to breakdown carbohydrates and protein.

Check out this post, 5 Non-Food Items to Avoid to continue supporting your digestive health and give your microbiome an upgrade. Like I said at the beginning of this post, these foods aren’t necessarily bad foods, but you may need to avoid them for a season to give your digestive system time to repair and heal itself before slowly reintroducing them.

What has improved your digestion? I’d love to hear about it in the comments below.

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