Hello, You have not mentioned the symptoms or past illness of your friend. However, since he is having severe pain and when pain comes he can t even walk, he is suggested to take rest. He should get clinically examined in ER, to detect appendicitis, UTI, GERD, pain due to food allergy, gastric ulcer, etc. He should get Urinalysis (C/S and R/E) , CBC and required imaging tests done. If it is appendicitis he may need surgery. In the meantime, he should stay well hydrated and well fed (he can take custard, oats meal, porridge, pudding). Take food that is easily digested. He should not take spicy, oily, junk food. Stay away from red meat, full fat dairy products, etc., for a couple of days. He can take spasmol (spasmoproxyvon), one SOS when pain abdomen. To ease discomfort he can take PPIs, one SOS when required. If UTI is detected he will need a course of oral antibiotics. Get him treated at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician