I'm not sure that immodium is strictly for loose D. Doesn't it slow down peristalsis, calm your bowels down and reduce urgency?
If it can do only one of the above then it should be a must for people who are invariably in flare situations.
The toxic megacolon risk would be a result of overdosing with severe constipation or even worse---a blockage in the bowel.
If that ever happened, I think you would be having seriously painful symptoms at an early enough stage to get to the hospital and get it dealt with.
69m Dx'd may'06 (prob had since'04)
150mg azathioprine-stopped jul28-11
.05mg Lorazapan nightly to help sleep
on and off pred last 5 yrs
started 25mg MTX/folic acid Oct'11-stopped after 3 mo.
started 15mg pred mar4'12
1st infsn. Remicade mar8'12
2000mg vit D daily
800mg calcium daily
Slip. elm daily
Psyllium seed and/or metamucil/benfiber daily