Hello, Raspberry contains a pigment called anthocyanin. It can cause discoloration of stool. Your stool might appear darker or even black. It is a temporary condition, there s nothing to worry. However, the hardening of stool is indicative of dehydration. Increase the amount of water and fluid intake. It will help bowel move easily. Take some fiber supplements. Raspberry contains natural fiber that helps in better digestion. You can take laxative at bedtime to get relieve from hardening of stool. Your symptoms should get reduced. In case the symptom is persistent, you are advised to get clinically examined by a physician, get stool examination (R/E and C/S), and required imaging tests done to detect any internal injury or bleeding that may be causing symptoms. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K, General & Family Physician