What Causes Skin Rashes And Irregular Bowel Movement While Using Medicines For TB?

I am a patient on anti TB treatment ( for intestinal TB)for the 16th day running, on a combination of

Akurit - 4, 4 tablets daily on empty stomach
Rabium plus 1 tablet daily on empty stomach Pyricontin 1 tablet daily any time during waking hours.

I have two unusual things for the last 5 days. The first is the prickly dry rashes that have erupted on the lower back, inner thighs and elbows.
Second is about the bowel movement. Each morning for several years now, I have been inducing a free flow of bowels by drinking a cup of warm water, due to chronic constipation. But the last 15 days the bowel movements have become highly irregular with bloating and 4-5 movements a day.
Could you advise if these symptoms are side effects of any of these drugs