I have been in your spot. IT's awful when things feel hopeless. I have a few suggestions if you have IBS-d. Try Questran in powder form. I did this for two years and had minimal symptoms. I took two scoops two times a day. 2. Try lomotil These first two need a script from the doc. 3. Try Caltrate plus 500 or 600 with Vit. D and minerals. Start at a half tab 3 times a day and work up. Please note it must be Caltrate or its exact equivalent. To figure this out you would have to look at the active ingredients. THere are many similar ones which won't do the trick. Hope this helps! Please let me know.
Have you tried a very high fiber diet? That would really help the constipation. Also increase your fluid intake.... soda with caffiene is an irritant to the colon and might help move you along better.