Yes peanut butter is hard to digest especially for people who have digestive issues.
If your digestive health is in good shape then peanut butter is not really hard to digest but peanut butter does take a bit longer to digest than other foods.
If you have digestive issues then peanut butter can be harder for you to digest.
The Trans fat in peanut butter is a number one cause of inflammation in some peoples bodies so the more peanut butter you eat the more likely you are to get inflammation.
The inflammation from the trans fat and peanut butter can lead to bloating, gas, and general digestive discomfort.
Peanut butter in moderation though is healthy and does have some health benefits but eating too much peanut butter can be bad.
Also too much peanut butter may cause weight gain as well.