I would stop taking the bentonite clay. You may be like me and have a slight gluten allergy along with colitis. Bentonite clay may be obstructing and scratching your intestines. Have you seen a doctor?
Try cutting out gluten for two weeks and see if your stool changes. If that doesn't work, google common food allergies; you could try cutting out either dairy, nuts, citrus fruits, very acidic or spicy foods, or other foods you may have a hunch are irritating your bowels one by one to narrow it down. Acidic foods especially can irritate the bowel and I think can cause some problems when the stomach tries to empty its contents into the bowel. Supplementing your diet with more dark leafy greens, beans, and broccoli may also help supplement your body with more folic acid so it can digest food properly. Also, I would recommend a good probiotic such as Philips' Colon Health. Bacteria may be what you need to get you more regular again. With the probiotic I take one tablespoon of coconut oil, which seems to help calm my stomach. For my symptoms, many times I also pick up coconut water (no sugar added) which contains magnesium. Magnesium not only helps soothe inflammation in the bowel, it helps hydrate your body. Hydration helps your body pass bowel movements more efficiently. If you dislike coconuts, definitely pick up some Pedialyte.