I have been diagnosed with irritable bowel syndrome. could this potentially ruin my career and further study?

R/O other diseases : First make sure you don't have celiac disease or colon cancer. Then experiment with various food. Many people decrease symptoms by finding foods that don't cause the symptom. Things like spicy sauces, fruits, but also almost any food can cause symptoms. You have to try to find what works for you. If either diarrhea or constipation is your main symptom there are medications that may help.