Bless you for trying to help this man out.
I feel he not only should continue the parasite cleanse for what he feels are in his stomach but he needs to get the pancreatic flukes out to help with his diabetes. Ask him if he feels kinda like a movement and/or poking sensations around his stomach.
His toes may hurt more because roundworms make nest in the feet(and fingers) and then the adults will wrap around toes, when these adults move around my toes they hurt, there isn't room for them and the nest areas vibrate almost non stop(I know this because Hanna Kroeger says it in her book and over the past two years I have found it to be true with me). Sometimes the nest will make walking strange, you feel a squishish feeling when you stand or walk, makes you wavier and will make you off balance.
I also doubt if the doctor will help much, stool samples should only be done around a full moon and after parasite herbs have been taken so that things will show up in the stool. But if the lab doesn't know what they are looking for, which most don't it will show up negative.
Tell this man that herbs are food and will help him, they will be giving him nutrients at the same time that his body may need. Do the parasite herbs only twice a month during the full moons and I would add the herb elecampane ( kills roundworms good).
I have never seen a Tapeworm over two years, but I was very bloated and hungry. After I expelled many roundworms this all went away, but it took over a year for me to really get over this.
I have taken the Co-Q10 many times (it is very expensive) Hanna Kroeger makes a formula called rascal(around $10.) that is suppose to help if it is a tapeworm. I have taken that also (just in-case I had one) There is a web site where you can buy her supplemtnts www.hannasherbshop.com, my heath food store carries these also.
Only you know what his health is like so you will have to decide if he can handle the large dose of Co-Q10. Hanna Kroeger's pills are capslues so they can be opened and put in food. (I give my dog a daily dose of Wormwood combo on top of her food and she loves it.) I would sure try to get him to continue taking the parasite herbs, what does he have to lose, except bad health, and gain quality of life.....he really needs to get the flukes out...keep trying you are a blessing in his life...~hugs~ heyjude