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.
Best Answer: The symptoms of lactose intolerance can manifest anywhere from 30 minutes to 2 hours after ingestion of lactose containing food. The symptoms can last up to 3 days following ingestion. I hav answered a similar question regarding lactose intolarence previously. U can please see the link below.