constipation - azirut

Hi, My baby is 6 months old and he is bottlefed from about one month onward (the first month he was breastfed) he has been suffering from constipation since changing from breast to bottle and i know that it is quiet common. still i am very worried because now he is nearly six months and i understood that it should have been over by now. He has bowel movement once in 3-4 days and the last time i noticed a wound in his rectum passage. I live in london and i was advised here to let him drink some orange guice, prune guice or freshly squeezed tomato. still, nothing works and it is only temporary solution... Is there any reason to worry ? what do you recommend me to do ? His poo =kaki is very firm and solid. p.s. i can tell that he is quite stressed while doing poo. I will very much appreciate an answer even better if it will be in hebrew

כדאי לנסות לתת תחליף חלב אם אחר - לעתים זה עוזר. כמו כן יש לטפל בסריטה בפי הטבעת - anal fissure הטיפול הינו מרככי צואה כגון avilac duphaalac paraffin oil ומשחה אנטיביוטית מקומית. כמו כן בגילו כדאי להתחיל לתת ירקות שמכילים סיבים ומרככים את הצואה