Immodium and Lomatil are the same thing and it is a mild opiate. The generic name is Loperamide and someimtes Lopermide based meds contain an anti-gas component called simethicone.

Go here for more info from wikipedia:
Loperamide

A useful remedy for the runs is called the BRAT Diet or the B.R.A.T Diet.
>>The BRAT diet is a historically prescribed treatment for patients with various forms of gastrointestinal distress such as diarrhea, dyspepsia, and/or gastroenteritis. The BRAT diet consists of foods that are relatively bland, easy to digest, and low in fiber. Low-fiber foods are recommended because foods high in fiber may cause gas, possibly worsening the gastrointestinal upset.[1]
BRAT is the mnemonic acronym for Bananas, Rice, Applesauce and Toast, the staples of the diet.[1] Alternative BRAT diet formulas include BRATT (Bananas, Rice, Applesauce, Tea, and Toast) and BRATY (Bananas, Rice, Applesauce, Toast, and Yogurt).<<
Specifics on the BRAT Diet Regimen