Dr's what is your opinion on letting babies cry it out? Our baby is 6 weeks old, my husband says let him cry it out but I think he's too young?

Yes he is too young. at this age something could be bothering him, most commonly thirst or hunger, not getting enough, or excessive gas in his stomach that needs to be expelled, then he might need a bath to calm him down, also check around all over his body for anything unusual, especially his private parts, penis and testicles not red or inflamed, are they in place, if after all this nothing is noted see his doctor.