Hi, Welcome to HCM. Your doctor is right to some extent that diabetics are prone for fungal infection, but more commonly yeast infection. Moreover, diabetes as such causes an immunocompromised state which predisposes them to opportunistic infections like dermatophytic infection or ringworm infection. Dermatophytes usually spread by contact and is more common in areas where there is increased sweating. Symptoms of hiatus hernia are not related to diabetes nor ringworm infection. Increased pressure in the abdomen such as from obesity, coughing, or straining during bowel movements may play a role in causing hiatus hernia. I hope I have cleared your doubts. Thanks.