I know this is an old post but if you still visit this forum, I just wanna say if colitis holds you back in your own day to day life, it will surely hold u back in a parenting way. Even if u have family members to help you, that might change in the future, then what if u cant cope by yourself? Unless u feel you would be upto going out every day taking your child to school every morning, picking them up every afternoon, taking them to doctors, dentists, hospital appointments, shopping trips when they get older, out to the cinema, ice skating, holidays etc etc, if u cant cope doing those normal parenting things, it isnt fair on the child. They will resent you even if they understand u have health issues, because its always like 'but mom u could have tried harder, u could have made my sports day at school like all the oher kids moms did' that upsets kids and they get angry.
Another thing is what if you pass your condition onto your child? I dunno if it runs in families, but u should check. In that case its totally selfish to get pregnant and put someone else through having that illness, when you could foster or adopt instead, and still be a mom to someone who needs/loves u. Thats my opinion anyway.