Help please he is only 4 months old..he was born at 7months

He had a little blood when he pooped. I didn't know he was a little constipated or something because he didn't cry. I seen it when I changed his diaper. I'm worried because I have no way to get to his pediatrician or ER. Is there anything I may give him or put on him apart from diaper rash cream to help him. No rude comments please.