Clostridium is a bacterial infection that can be hard to get rid of. Panacur is a dewormer, so I'm not sure of it's repeated use for your dog. Metronidazole and other ABs are recommended for treating Clostridium... also dogs can become resistant to the AB and a change may be helpful. I'd also eliminate all treats and chews from her diet until she is cured.
Pumpkin (1 tsp/meal) may help to firm up the stool. The other OTC meds may prevent the ABs from being as effective, so I'd check with your vet and work closely with him to get this resolved. Coconut oil in the diet may help once the course of antibiotics is finished, as it coats the intestines.
Clostridium in Dogs Treating Clostridium in Dogs with Amoxicillin