Hello Thank you for posting your query on Health Care Magic Internal anal achalasia is a surgical disorder. The treatment options include dilatation under anesthesia or sphincterotomy. It is not a common diagnosis kept by surgeons also and therefore you need to be sure before reaching this diagnosis. More commonly it is referred as a short segment Hirschsprungs disease. Making it simple you should show your child to a pediatric surgeon for proper diagnosis and treatment. Tests include a barium enema (a radio-opaque dye is put through anus and films are taken), anal manometry (measuring the pressure in the anus) and if required, a small biopsy. All this is essential before labelling any achalasia. And if it is so then its treatment is surgical. The constipation which responds to laxatives only is usually diet related. You should give a lot of fluids and fibres to your child (green leafy vegetables, carrots, papaya, other fruits). Hope this solves your query God bless you