red footed tortoise bowel movement

Question
I'm taking care of a tortoise for a friend, so I'm not too familiar with this animal, but I have seen it move its bowels enough to know that the feces is usually a brown goo.

All day today and yesterday he was fairly reserved and lethargic and stayed in one corner of his habitat away from the heat lamp. He moved so little that I thought he was stuck but he kept going back to the same spot. He also seems to go every time he leaves his habitat, but today he was really straining when I let him out and put him on a towel. He passed a sort of orange paste with pieces of whole pea (his favorite food is frozen peas) shell in it! He was also breathing hard and seemed to be visibly straining.

Is this normal or due to stress of some kind? Should I just wait for the problem to go away or take him to a reptile vet? I'm going to start letting him out on a towel regularly in case he has a sort of sanitary instinct or something. Do they have that kind of sanitary instinct?

Answer
 From the description of the feces, he's obviously not digesting his food well.  If he's too cold, he won't.  And steering clear of his basking spot is making him cold.  Straining also concerns me.  The vet should see him.  He could have parasites from stress, or the basking area is too hot, or tummy trouble from diet.  Also, how is he set up?  Does he have access to water?  does he have adequate UVB lighting?  Red-foots, like mant reptiles need good UVB to metabolize nutrients in food.  If your friend gave you the setup for him, how old is the light?  UVB lighting should be changed every 6 months.
 It's a good idea to take him to the vet.  Only he can rule out the possiblity of parasites or possible blockage.
If you are unsure of the age of the UVB, I would suggest you change it anyway.  Use a digital thermometer with the probe right on the basking site to make sure it's 90F.