Completely normal when introducing foods especially with fruit or non starchy vegetables because it’s a natural laxative
It’s very rare to have fruit intolerances so most likely completely normal. Their digestive systems aren’t really ready until 6 months and even then you get weird and wonderful poops 🙈 my girl is 8 months and it’s a surprise every time 😂
The poos are usually a bit weird at the start until they get more used to it. I noticed with my son, he didn’t seem to digest things at the start because a lot of the times his poo would look exactly like the food he had eaten. I’d say maybe wait a little bit, and if you’re still worried try and cut out what you think he has an intolerance to and see if that helps.