Who knows what the right time for saying anything is?
The geat thing about blurting it out early on is that it frees you from all the anxiety about how you are going to tell people who you think may need to know. Getting it over with allows you to move on in a relationship without any hidden hang-ups. However, it is worth bearing in mind that there are a great many things you may not have said that could be equally important to you potential friends. An important thing to remember when talking about 'anything' is the old adage " It's not what you say- it's the way that you say it!' People often say that I am 'funny', or rather , they ask me if I know that I'm being funny. This is because I have the ability to keep a staight face at the same time as delivering relatively amusing conversation. I also have the skill and ability to inwardly laugh at myself and find the humour in adversity. I find that people appreciate this facet of conversation because it takes the pressure off them from thinking too seriously about any of the more difficult subjects, which touch us all from time to time.
I have just finished a booklet on 'Humour in sickness' which illustrates the importance of bringing a smile to people's faces and hearts in the face of the adversities accompanying illnesses. The idea that I can use my own experiences to bring amusement to others 'almost' makes having the problems worthwhile and it certainly help me to put a different perspective on the whole coping process.
Although I am not looking for a romantic relationship with anyone other than my wife (of 50years) I do like to make friends along my life's journey and I have never had any problems in mentioning my stoma and explaining it further to those who express an interest. Their verbal and emotional feedback suggests that they quite enjoy the amusing horror stories associated with 'toilet-humour', which is delivered insuch a way that clearly indicates that I have confidence and have no problems with it at all. It also indicates that I generally live a relatively 'normal' existence. (whatever 'normal' is!).
NB: I also have a whole repertoir of amusing conversational snippets about all sorts of other difficult conversational issues such as depression, death and dying, mental illness, bureaucracy, drivers, pollution and a whole lot more that I make up as conversations develop. It is my belief that making people smile is a gift and a skill that should not be wasted just because we may be suffering inside and out ourselves. Rather than pass on the suffering in conversation, I prefer to pass on the humour that is contained in every mishap and adverse situation. This humour often only manifests itself 'after' the event, when we can look back and see the funny side so it actually helps to have 'had the bad' and taken something better from it.
I hope my rambling on helps to answer your question and I also hope that you find someone who you can share your life with without worrying if you are doing the 'right' thing.