Hello and Welcome to ‘Ask A Doctor’ service.
I have reviewed your query and here are my thoughts.
Colostomy care in itself is a specialized ob and I am sure you must have been taught everything about colostomy care.
Constipation or altered stools are known to occur after any intestinal surgery and particularly after colostomy.
Since you have not mentioned other details about the cause of colostomy and others I can suggest you the following:
Continue Bene Fiber, 3 tablespoons is a large dose hence you may need another or additional
stool softener as well as laxative. Give a trial with all o find out the most suitable and most effective one for you.
Also identify the foods and beverages that cause constipation and stop these altogether.
Stress and
anxiety too have a role to play in proper evacuation hence keep these under control.
You may need enema through the colostomy if the X-ray shows fecolith formation.
I hope this answer helps you.
Let me know if I can assist you further.