DRUG CLASS AND MECHANISM: Diphenhydramine is an antihistamine used for treating allergic reactions. Histamine is released by the body during several types of allergic reactions and--to a lesser extent--during some viral infections, such as the common cold.
Symptoms Symptoms of lactose intolerance. The symptoms of lactose intolerance can occur after youâve eaten or drunk something that contains lactose. Symptoms of lactose intolerance may include: 1  feeling bloated. 2  pain or cramps in your tummy (abdomen). 3  diarrhoea. 4  wind. 5  feeling sick.
Symptoms of lactose intolerance generally develop about 30 minutes to two hours after consuming foods or beverages that contain lactose. Common foods and beverages that contain lactose include milk, ice cream, soft cheeses, yogurt, sour cream and any food that is made with dairy products.