Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your wee one’s situation, and wanted to help.
If you would still like assistance, can you tell me:
What did the diarrhea and vomiting look like? Any blood, black or coffee ground looking material?
Can he keep water down at all since you posted?
Are his gums pink or pale/white? Moist or sticky?
If you press on his belly,does he have any discomfort, tenderness, or tensing?
Could he have eaten something he should not have (ie bones, toys, plants, chemicals,etc)?
What dose of Imodium did you give? How much does he weigh? Any effect?