They work similarly - both act on the opioid receptor in the gut. Imodium is said to increase anal sphincter tone, though it doesn't do that for me, I think. Imodium is OTC while Lomotil is a controlled substance (at a modest level of control). Lomotil is a little more like the other opioids; for example, it reduces withdrawal symptoms in opioid addicts. Lomotil has a bit of atropine added, which is usually fine at the prescribed doses but (by design) very unpleasant at higher doses.

Neither of these drugs seem to carry the risks with long term use associated with their cousins that are used for pain relief (morphine, oxycodone, codeine, etc.).

I suggest you try both and see which one works better for you.

I found that lomotil actually gave me diarrhea, it is a side effect, oddly. Wal-mart brand immodium works best for me and is cheaper than name brand. it's the only thing I even go to that store for it works so well.

Everyone is different, I agree with Scott, try them both and see which you prefer.

I use Loperamide which is prescription Imodium. I think it works better because it is in capsule form and makes it into my system faster. I've never tries lomotil so don't know the difference. I don't need to use it when I'm taking antibiotics but do use 2-4 per day when I'm not taking them. All of us are different and it's been trial and error and what am I eating etc. I wish there was a manual we could follow!