Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Constipation is commonly seen in patients with associated psychiatric illness. You can give him laxatives lactulose syrup thrice a day. You can also try newer drugs like Prucalopride which has better efficacy and available over the counter. Ask him to take more fiber rich foods in his diet .If the constipation persist even after laxatives,better to go for an ultrasound scan to look for any fecal impaction or obstruction. In that case he might require enema to pass impacted fecal matter. Hope I have answered your query. Let me know if I can assist you further.