I hope the oatmeal works for you. Kinda reminds me I need to eat some myself. A new medication has changed my normal functions. Bananas are a great source of potassium and fiber. It's truly amazing how our bodies are the same but they react differently to things. Make sure you are drinking enough water.

I have a sensitive gut so normally I have the opposite issue.

For me kiwi fruit and those seeds are deadly as well as stone fruit. Again they are a great source of fiber. Even pickles......
PS. Never forget good old baked beans ..... Try making lentil soup too.