Hello! Thank you for the query. Generally IBS can be diagnosed when all other possible reasons are ruled out. So you should have blood work, liver tests, pancreas tests, thyroid tests, abdominal CT with oral contrast (enteroclysis), colonoscopy, stool test, stool culture test. Rifaximine treatment should be also tried. If all this tests have been done, you can say IBS is your problem. Mucus discharge is quite characteristic in case of constipation. Its because intestinal cells do produce the mucus, no matter if the stool is passing or not. So when the stool remains in the same place, only mucus comes from intestine. When laxatives do not help, and it it lasts a week now, you should see a doctor. Abdominal Xray should be done to rule out an obstruction. Enema and fluids should be given along with Metoclopramidum and smooth muscles relaxing medicnes. You can also try to massage your abdomen (this should stimulate bowels to work) and take a hot bath. Drink plenty of mineral water. Hope this will help. Regards.