I seem to get horrible diarrhea a few times a month now. What kind of food would be good for my bowel if it's IBS?

IBS. IBS is a diagnosis of exclusion. You need to have parasitic diseases, celiac, food allergies and inflammatory bowel disease ruled out along with other problems such as an overactive thyroid. Helpful foods are bananas, rice (white), apple sauce, tea and dark toast. Fiber such as psillium is sometimes helpful by bulking the stool.
Fiber. Try increasing fiber in your diet. If things persist, you may want to try eliminating gluten or dairy from your diet to see if helps. Also ask your doctor, you may need some blood tests to check for other causes of diarrhea. .