answer:Here is a website that explains What is Anal Itching? From the description, it might be caused by: Abrasive rubbing – cleaning your bottom with toilet paper can aggravate anal itching if the sensitive skin area is rubbed too hard, for too long, or too often. Type of toilet paper – the texture and substances added to toilet paper may irritate and inflame the skin in the anal area, resulting in itching. The other causes listed are worth sharing with him. To get that kind of stool, it sounds like something he ate didn’t digest well, particularly if it was a spicy food.