This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition, Subject name: Medicine
Following drugs are used in IBS-Constipation Except 
Select and explain. 
A. Lubiprostone, B. Tegaserod, C. Alosetron, D. Linaclotide
C: Alosetron
Answer: C: Alosetron 
Explanation: DRUG MECHANISM OF ACTION USED INTEGASEROD 5 HT4 AGONISTIBS -CONSTIPATIONLUBIPROSTONE STIMULATOR OF CHLORIDE CHANNELIBS -CONSTIPATIONLINACLOTIDE GUANYL CYCLASE C AGONIST IBS -CONSTIPATIONALOSETRON5-HT3 ANTAGONISTIBS-DIARRHEA