3 Years Old Baby Suffering From Constipation And Stomach Pain

Hi , My son aged 2 Yrs 7 months is having constipation , we have tried homeopathy but that did not worked. We have tried Liv 52 drops for about 15 days and no longer use it now. He is having hard stool and with pain and sometimes blood also seen in stool. He is 11 Kg but is active throughout the day and Learn Numbers , Rhymes and Play well. His sleep pattern is not sound from his infant stage. But he takes sleep for about 8 Hrs and in between woke up once or twice and ask for milk. Now apart from milk diet he has started taking daal, rice ,half boiled egg, roti, banana, biscuits etc in his diet but sometimes miss on them in a week. Though it is tough for her mother to make him eat while telling him tales and stories. Recently one of GP has recommended looz solution 5 ml daily at bed time for 10 days and then suggested to give looz in gaps maybe after 3 days. What do I do ? Please suggest. One medical history is that he had once had convulsion or febrile seizure when the fever jumped to 103. This was last year in August 2010 when he was 1 yr 9 months old. We do fever management for febrile seizure to avoid it now by giving crocin syrup and Frisium 2.5 Mg , whenever he got fever. However he got fever only because of seasonal cold or stomach pain sometimes. There is no convulsion after that. Please suggest on constipation and also if he could improve his appetite and also how he can gain weight.