Problem: How does the sentence end?

The syrup irritated his throat, but the pill made it feel better, because the 
Answer: pill was so soothing.

Problem: How does the sentence end?

During the winter season the professional was shopping for a new coat but not a shirt because the 
Answer: coat was trendy.

Problem: How does the sentence end?

The drying machine was disposable at this point, but we still relied on the washboard, as the 
Answer: washboard was essential at this point.

Problem: How does the sentence end?

So 
Answer:
Brian trashed the house because Craig wants to live in a clean environment while Brian was messy.