Do loose stools mean a guaranteed end of constipation?

Not necessarily. If you have an impaction of hard stools that is incomplete, only liquid stool can get by the plug of stool. The mistake is to take something to stop the "diarrhea" which will plug you up fast. Use a plain fleet enema (sodium bisphosphate) or glycerine suppositories to make sure your rectum is empty before trying to control the diarrhea.