What can we do to fix this situation? He is in a lot of pain when passing stools. He only goes to the bathroom once every two days.

To help resolve the situation with someone experiencing discomfort during bowel movements, you could increase their water intake by offering it more frequently or diluting their milk a bit to encourage them to drink more. Adding prunes to their diet may also be beneficial. If these methods do not work, you can try using a safe over-the-counter product like Lax A Day, which can be obtained at a pharmacy. The pharmacist will be able to calculate the appropriate dosage based on the individual's weight.