Have Been Farting A Lot That Leaves Stains And Sweaty Anus. Have Normal Stool Test. Underlying Cause?
A few more information from you will be more helpful in solving your problem :
1) Do you eat frequently from outside such as fast and fried food ?
2) How is you bowel habits ? Do you have loose motions and constipation in alternating bouts ?
If the above are true, then I would like to suggest a high roughage diet along with plenty of liquids for you as your diet.
In the meanwhile you can go for a routine stool test for ova and cyst. Your symptoms could be due to amoebiasis which is not infrequent now a days. This can be treated with some anti amoebic drugs if need be.
Also you can go for regular exercises, a high roughage diet as already explained, and a proton pump inhibitor along with a probiotic.
If you have got any other related questions, you are welcomed to ask. Awaiting for your reply. Good luck.