From what I have read in the literature, a tolerance to the GI effects of loperamide (Imodium) has not been observed. However, that does not mean that your symptoms cannot worsen to the point that it becomes less effective or ineffective. 

Tolerance is where you need to take increasing doses to achieve the same effect. This is what occurs with the analgesic effects of opioids taken long term. But the GI effects remain constant with opioids (this is why opiate addicts are so troubled by constipation).

Jan

During my many years of using Loperamide with & without a Stoma and now with a J pouch, I still take 3 or 4 per day, depending on consistency of output.

Only time I've taken six per day was over a 2 to 3 week period during a flare up before I was actually diagnosed with UC

I have to be careful with Imodium. It interacts with antibiotics and potentially other things to slow things down too much. I had some severe cramps after breakfast Sunday morning which I am convinced was from taking too much Imodium the prior night. It's sold over the counter so people assume they can consume it like candy, but nothing that impacts on your bowels like this should be consumed like candy. I use it very sparingly. It's also caused a partial blockage when I took too many. Trial and error as with everything but be careful with it.