Sensitive digestive system, fasting?

Ke

I know this is probably a dumb question, but I'm getting a little desperate. I'm having horrible stomach pain with no other symptoms with anything I eat. And it's very inconsistent and I can't pinpoint what ingredient. I seem to be fine with gluten, it seems it could be fruits and veggies? But could also be garlic and tons of other ingredients I'm eating. I'm already allergic to eggs and avocadoes. Nuts and bananas tend to give me an upset stomach too. I've had times like this in the past and the best thing for me is to do a type of fast. Bland diet of just unseasoned meats and cooked veggies. Or even just a liquid fast. I'm not looking to lose weight, just needing to feel better. But has anyone been able to do anything like this while breastfeeding? If I did like a nutritional drink instead of just a liquid fast could my milk supply be ok? I can't afford to get bloodwork done with my doctor at this time. I'm just nervous because already I'm eating less just to feel better, but worried my milk supply might be suffering. My daughter is a total chunk, so I know she's still getting plenty.