This is possible in some conditions.
He might have absolute constipation
which can give rise to fullness of abdomen and hard faecal maas may feel like lump in abdomen.
If more fat deposited in abdomen,there is bulging of abdomen.
Avoid constipation, take light purgative daily at night.take more green vegetables and salads.
If more fat in the abdomen,reduce weight,do leg raising exercise daily.