That is a disorder of chronic constipation
that occurs due to lifestyle or Gastrointestinal Factors.
If you are having dark coloured stools than have Stool for routine tests to check for any blood in it.
For constipation you should have plenty of water with lot of fibrous diet such as vegetables.
Take syrup Lactulose
30 ml every night to relieve constipation.
I hope I am sucessful in solving your query If you have further you can ask me.
Dr. Azhar Sattar